IMPROVEMENTS IN MAGNETO-DYNAMO ELECTRIC MACHINES
Year: 1878

page_text: LETTERS PATENT to John Imray, of Southampton Buildings, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN MAGNETO-DYNAMO ELECTRIC
MACHINES." A communication from abroad by the Societé Generale d'Elec-
tricité, of Paris, France, an Incorporated Company.
Sealed the 28th February 1879, and dated the 14th October 1878.
PROVISIONAL SPECIFICATION left by the said John Imray at the Office of
the Commissioners of Patents on the 14th October 1878.
JOHN IMRAY, of Southampton Buildings, in the County of Middlesex. "IM-
PROVEMENTS IN MAGNETO-DYNAMO ELECTRIC MACHINES." [A communication from
abroad by the Societé Generale d'Electricité, of Paris, France, an Incorporated
Company.]
This Invention relates to improvements in the construction of magneto-dynamo
electric machines, that is to say, machines for producing electricity by the appli-
cation of mechanical power, the object of the improvements being to render such
machines more efficient for the production of electricity with an economy of motive
power, to increase their durability, and to facilitate their repair. These results are
obtained by the adoption of novel forms and arrangements of the electro-magnets
employed, as will now be described. In a suitable framing two flat discs of copper
are fixed at some distance apart, and within them are other two discs fixed on a
rotating shaft, the latter discs being smaller in diameter than the former. To the
two outer and larger discs are fixed a number of electro-magnets spaced uniformly
round their circumference. Each of these electro-magnets consists of a core of soft
iron coiled with a fine insulated wire, the core projecting at each end beyond the
coil, and presenting an extended polar surface facing towards the axis of the machine.
The ends of the core are inserted into plates, which are fixed to the two stationary
discs by screws passing through slotted holes, so that the electro-magnets can be
adjusted and set nearer to or farther from the axis. The two inner and smaller
discs have in like manner a number of electro-magnets fixed on their outer periphery,

page_text: the cores of these electro-magnets being extended beyond the coils each way, so as
to present polar surfaces facing towards those of the outer magnets. The inner or
revolving magnets are equal in number to the outer stationary magnets, but they
are coiled with insulated wire of larger size. In order to reduce the force necessary
to separate the poles of the revolving magnets from those of the stationary magnets,
it is of advantage to use half the number of the former and to fix them obliquely,
so that while one pole of each is facing a pole of one of the stationary magnets, the
other pole of the former is facing the opposite pole of the stationary magnet next in
order. A certain amount of the inductive power is sacrificed by this arrangement,
but the force necessary to work the machine is notably reduced. The core of each
of these oblique magnets is conveniently made of iron, having a trough section bent
into the form of a U, and having a notch at opposite sides on the two limbs of the
U to receive the coil. Instead of coiling each core separately a bundle of the insu-
lated wires may be wound in a zig-zag manner over the one notch of each core, and
thence over the opposite notch of the next, and so on round the whole circumference
so as to include all the cores in one circuit.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Imray in the Great Seal Patent Office on the 12th April
1879.
JOHN IMRAY, of Southampton Buildings, in the County of Middlesex.
« IM-
PROVEMENTS IN MAGNETO-DYNAMO ELECTRIC MACHINES." A communication from
abroad by the Societé Generale d'Electricité, of Paris, France, an Incorporated
Company.
This Invention relates to improvements in the construction of magneto-dynamo
electric machines for producing electricity by the application of mechanical power,
the objects of the improvements being to render such machines more efficient for
the production of electricity with an economy of motive power, to increase their
durability, and to facilitate their repair. These results are obtained by the adoption
of novel forms and arrangements of the electro-magnets employed, as will be now
described with reference to the accompanying Drawings. Fig. 1 is a front view
partly in section, Figure 2 a longitudinal section, and Fig. 3 a plan of apparatus
according to this Invention, and the other Figures shew details and modifications of
parts, as will be hereafter explained. A, A, are two stationary annular frames of
gun metal tied together by cross ties a, and having fixed on them a number of soft
iron cores B coiled with fine insulated wire. The ends of the cores project forwards,
presenting extending polar faces close to the revolving electro-magnets. These are
fixed by their ends entering notches in the frames A, in which they are secured by
setting screws v. A rotating boss D carries a number of electro-magnets C shaped
like the coiled cores B, and equalling them in number, but larger, and coiled with a
larger wire, producing induced currents in the finer wire of the coils B. The electro-
magnets C may be of U form, as shewn in perspective at Fig. 4, and in
side view and plan at Figs. 5 and 6, and in that case there are half as
many of them as there are coils B. In all cases the electro-magnets C are
fixed obliquely on the boss D, or the coils B are fixed obliquely, or both B and C
are fixed obliquely in opposite directions, so that each electro-magnet in its rotation
passes from the influence of one coil B to that of the next without suddenness of
transition. A certain amount of inductive force is thus sacrificed, but the result of
this arrangement is a considerable saving of power in working the machine. The
coiled portion of the core B may also be of U form, as shewn in the section Fig. 7.
Instead of coiling the U shaped electro-maguets, as shewn in Figs. 4 and 5, they
may be coiled as shewn in the plan Fig. 10, the cores being shaped as shewn in per-
spective end view at Fig. 8, and in side view at Fig. 9. According to this arrange-
ment the wires are formed into a bundle, which is wound in zig-zag fashion over
the alternate ends of the cores, and the end wires of the bundle are connected in
such a manner as to make the whole into one circuit as if each wire were separately
wound. As shewn in Figs. 1, 2, and 3, the electro-magnets form parts of the
periphery of a drum D, having oblique grooves c in which the wires are wound,
the coiled cores B being also placed obliquely. The electro-magnets B instead of
having only two poles, one at each end, may have three poles, as shewn in Fig. 11,
the two end poles c, c', being of one name, and the middle pole c being of the
opposite name. Fig. 12 shews a plan of two such coiled cores as they are placed
side by side facing the revolving drum, having the oblique grooves e for the electro-
magnet coils, which in this case have increased obliquity, so that each is within the
influence of three of the coiled cores e, which are parallel to the axis of the drum.
The currents produced by the action of the machine are collected by the wires f¹
to the insulated rings x.
Having thus described the nature of this Invention, and in what manner the same
is to be performed, as communicated to me by my foreign correspondents, I claim
in the construction of magneto-dynamo electric machines of the kind herein.
described,-
First. The combination of the coiled cores B, having their uncoiled ends projecting

page_text: forwards and presenting extended polar faces, with the similar revolving electro-
magnets C with their polar faces close to the former, substantially as herein
described.
Second. The construction of the electro-magnets in U form, as described with
reference to Figs. 4 and 5 and Figs. 8 and 9 of the accompanying Drawings.
Third. The method of winding the insulated wires of the electro-magnets as
herein described, with reference to Figs. 8, 9, and 10 of the accompanying
Drawings.
Fourth. The oblique setting of the electro-magnets or of the coiled cores, or of
both, as and for the purposes herein set forth.
Fifth. The construction and arrangement of the coiled cores, presenting three
poles, as herein described with reference to Figs. 11 and 12 of the accompanying
Drawings.
In witness whereof, I, the said John Imray, have hereunto set my hand and
seal, this Tenth day of April, in the year of our Lord One thousand eight
hundred and seventy-nine.