Improved Construction of Electric Alternating Current Generators.
Year: 1897

page_text: Date of Application, 18th June, 1897-Accepted, 31st July, 1897
COMPLETE SPECIFICATION.
Improved Construction of Electric Alternating Current Generators.
I, OTTO TITUS BLATHY, of II Hauptgasse 73, Budapest, Hungary, 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:
This invention relates to a construction of alternating current generator with two
or more armatures and a single magnet wheel, the relative arrangement of these
parts being such that one and the same magnet wheel induces in the two or more
armatures two or more alternating currents of one or more phases, and having
different frequencies. By this ineaus it is rendered possible to supply, from one and
the same machine, alternating currents of low frequency, applicable for example for
the performance of mechanical work, and alternating currents of higher frequency,
applicable for example for electric lighting.
I will describe the said construction with reference to the accompanying drawings,
in which Figs. 1 and 2 show respectively a longitudinal section and a part front view
and part cross section of one arrangement.
In these Figures :-
:-
F is the iron core of the magnet wheel, P1 and 12 the divided polar extensions or
shoes. S the stationary field magnet winding, f the annular body common to both
armatures. the divided polar shoes of the one armature, & the armature
winding apertaining thereto, p³ the divided polar shoes of the other armature, ² the
armature windings apertaining thereto.
:.
The essential feature of this new construction consists in that the number of the
magnet polar extensions P and P2 is different in the two halves or in the two
opposite poles of the magnet-core with single winding; for example, in the construc-
tion shewn, there are twice as many polar extensions P2 opposite the armature pole
shoes p AS there are polar extensions P¹ opposite the armature pole
shoes pl.
In a corresponding manner there are twice as many armature windings &² as there
are arinature windings 8.
The left hand side of Fig. 2 shews the end view of half of the magnet wheel
viewed from the left hand of Fig. 1, and on the right hand side it shews a sectional
end view of half of the magnet wheel viewed from the right hand of Fig. 1.
From
this it will be seen that the left hand side of the magnet wheel has six polar
extensions and the right hand side twelve so that the number of alterations produced
in the windings 82 will be double that produced in the windings 81.
Figs. 3 and 4 shew similar views of a modified construction for the production of
three-phase alternating currents, the number of polar alternations of which are
proportioned as 3 to 7.
The parts are designated in the same manner, as in Figs. 1 and 2.
In a similar manner, the one armature may be arranged to deliver single-phase
currents, and the other polyphase currents of different frequency.
Figs. 5 and 6 shew similar views of a modification in which both the magnetic
field and the armature are stationary, only the divided magnetic bridge pieces BỊ

page_text: and B2 being made to revolve. With this construction the number of the bridge
pieces B¹ must be different from that of the bridge pieces B2; the drawing shews
the proportion of these numbers to be 3 to 8.
:
Figs. 7 and 8 shew similar views of a current generator constructed according to
the above described invention in which there are three armatures having respectively
poles p p² and p³, and a magnet wheel with two windings S and S¹, and three rows
of polar extensions P1 P2 and P3; such a machine can deliver three single or
polyphase alternating currents of different frequencies.
In a similar manner generators for four or inore single or polyphase alternating
currents can be constructed.
The details of construction of all the above described arrangements may be of any
well known kind, and need not be farther described.
With the above described invention it is immaterial whether the magnet winding S
be fixed or be made to revolve with the magnet wheel; also, whether the armature
be fixed while the magnet wheel revolves, or vice versa, and whether the magnet
poles or the armature poles are placed internally, or whether these poles are arranged
laterally opposite each other.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what I
claim is
An alternating current generator for the simultaneous production of two or more
single or polyphase alternating currents having a frequency differing from each
other, consisting of a magnetic field with single or multiple winding, and a double
or multiple armature, the number of the polar extensions or polar bridge pieces of
the field magnet which induce the currents in the one arinature being different from
the number of the field magnet polar extensions which induce currents in the other
armature or armatures, while the number of windings of the several armatures are
also made to differ in a corresponding manner, substantially as described.
Dated this 16th day of June 1897.