Year: 1888

page_text: nature of this invention to be as follows:—
This invention has for object improvements in multipolar Dynamo-electric machines,
and has reference, principally, to the employment of a number of magnetic fields of
force equal to half the number of the poles, in contradistinction to other machines of
this class which require as many fields as there are poles.
This improved arrangement offers the advantage of enabling the energy expended
in effecting the excitation of the machine to be diminished by half without however
weakening the electro-motive force of the dynamo, since the field magnets may be
formed so as to permit of the field of force being completely utilized, each of the
poles forming part of a magnetic circuit which is completely closed by the medium of
the iron of the armature core.
The invention has reference also to the method of collecting the induced currents
either by three brushes, or by two pairs of brushes, suitably arranged in such a way
that the current circulating in the armature traverses only the active coils, that is to
say those in which induction is taking place.
With this arrangement of brushes the constants of the dynamo may be varied
without changing any connections, by a simple coupling-up of the brushes for electro-
motive force or for quantity.
Fig. 1 of the drawing which is annexed by way of illustration shews a dynamo
with six poles constructed according to this invention. This machine is provided with
three field magnets or inductors A, B, C, quite independent of one another. The
Figure also illustrates the arrangement of each of the magnetic fields; the arrows in
full lines indicating the direction of the propagation of the current in the armature.
In order so simplify the drawing, there are shown only 24 elementary bobbins, and
the same number of segments or commutator plates in metallic connection in sets of
three each, so as to couple-up for quantity the bobbins situated at the three apices of
each equilateral triangle which can be formed out of the groups of bobbins.
The traces in full and broken lines represent the elementary bobbins, and the plates
of the commutator together with the method of coupling.

page_text: The small dotted arrows indicate the direction of the current induced before each
of the poles in the convolutions of the coils shewn in full lines.
The arrows 1-2, 1-2, and 111 211 show the direction in which the current is
propagated in the ring armature.
The induced currents of the six parts of the armature are collected by two pairs of
brushes fixed in such a manner that one of the pairs is situated at or over a pole of one
name, and the other pair at or over another pole of the opposite name.
Fig. 2. illustrates diagrammatically an improved dynamo-machine according to this
invention. A machine with six poles has been chosen by way of example. It has
been stated above that the arrangement of the inductors or field magnets is such that
each field of force forms a magnetic system quite independent of the others and is
closed upon itself by the medium of the iron of the armature.
The dynamo shewn in the drawings comprises three flat or curved field magnets
quite independent of one another, and so disposed as not to offer any consequent
poles.
This arrangement thus permits of the pole pieces being of the most suitable shape
for avoiding all loss by the distortion of the lines of force produced.
On making a section m, n, (Fig. 2) through the iron of the ring armature, between
two poles of opposite names belonging to two adjacent electro-magnets, it can be
demonstrated by the aid of the improved magnetic explorer (forming the subject of a
recent application by me for Letters Patent number of
) that
the intensity of the field of force is practically nil in all the parts of the armature
situated between two poles of opposite names helonging to two different field magnets
whilst it is at its maximum for all the parts of the iron of the ring armature situated
between the poles of the same field magnet.
Each of the fields of force forms a closed independent circuit, and poles o opposite
names do not divide the circumference into equal parts as heretofore in such machines.
This is a distinguishing feature of this invention.
If the dynamo has six poles and consequently three independent fields of force,
each of these fields of force may comprise an angle of about 120 degrees.
In this manner two pole-pieces of opposite names belonging to two adjacent field
magnets can be brought into very close proximity to each other, without the field of
force of each of them ceasing thereby to remain independent and to form a closed
magnetic circuit.
The elementary sections of the ring armature are connected in sets of three each,
in the form of an equilateral triangle as shewn in Fig. 1, if the dynamo has three
magnet fields; and in sets of four in the form of a square, if the dynamo has four
magnet fields; and in general in sets of n each when they are n independent fields.
In each case the poles of opposite names of two adjacent field magnets are merely
arranged symmetrically to each of the radii which divide the circumference into as
many parts as there are magnet-fields.
་
In the example shown in Fig. 2, the circumference is divided into three parts by
the radii OX, O X, OX", and the poles of opposite names A and B, C and D, E
and F are symmetrical to the straight lines OX, O X¹, 0 X".
This symmetry is necessary in order that the sections of the ring armature connected
for quantity may be all at the same time in points where the fields in the intervening
iron have the same intensity.
•
The induced currents are collected by means of three brushes K. L. M, the outer
ones K and M being connected for quantity and forming one of the poles, the middle
brush L forming the other pole of the dynamo.
360°
The outer brushes are at the most 120° apart, or at if n is the number of magnet
n
fields. In certain cases it is advantageous to employ four brushes as shewn in Fig. 1,
in which the brushes are coupled-up for quantity b and b', and b₁, with b₁'. The former
are situated at a north magnetic pole and the two others at a south pole.
The current circulates in the outer circuit as shewn by the arrows 3, and in the

page_text: armature as shewn by the arrows 1, 2, 11-21, 11-211. All the coils situated in the
neutral regions a, ß, a¹, ẞ', a", ẞ, are not traversed by any current.
In this case the dynamo produces a current having an electro motive force E and
intensity I; but when the brushes are coupled up for electro-motive force, that is to
say b is connected to b₁, and the two others are taken as poles of the dynamo, the
machine will produce at the same speed a current of an electro-motive force of 2 E
and of intensity I.
This coupling of the brushes for electro-motive force or for quantity which can be
effected instantaneously by means of a commutator, renders it possible whilst going
at the same speed to either double the electro-motive force by diminishing by half the
output, or to double the latter by diminishing by half the electro-motive force.
Dated this 2nd day of March 1888
W. LLOYD WISE,
Per J. E. Stokes,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.

page_text: Improvements in Multipolar Dynamo-electric Machines.
I, GEORGE MIOT, 72, Boulevard Haussman, Paris, France, 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 for object improvements in multipolar dynamo electric
machines, and has reference principally, to the employment of a number of magnetic
fields of force equal to half the number of the poles, in contradistinction to other
machines of this class which require as many fields as there are poles.
This improved arrangement offers the advantage of enabling the energy expended
in effecting the excitation of the machine to be diminished by half without however
weakening the electro-motive force of the dynamo, since the field magnets may be
formed so as to permit of the field of force being completely utilized, each of the
poles forming part of a magnetic circuit which is completely closed by the medium of
the iron of the armature core.
The invention has reference also to the method of collecting the induced currents
either by three brushes, or by two pairs of brushes, suitably arranged in such a way
that the current circulating in the armature traverses only the active coils, that is to
say those in which induction is taking place.
With this arrangement of brushes the constants of the dynamo may be varied
without changing any connections, by a simple coupling up of the brushes for electro-
motive force or for quantity.
Referring to the drawings filed with my Provisional Specification
Fig. 1. illustrates a dynamo with six poles constructed according to this invention.
This machine is provided with three field magnets or inductors A, B, C, quite
independent of one another.
The Figure also illustrates the arrangement of each of the magnetic fields; the
arrows in full lines indicating the direction of the propagation of the current in the
armature.
In order to simplify the drawing, there are shown only 24 elementary bobbins, and
the same number of segments or commutator plates in metallic connection in sets of
three each, so as to couple up for quantity the bobbins situated at the three apices of
each equilateral triangle which can be formed out of the groups of bobbins.
The traces in full and broken lines represent the elementary bobbins and the plates
of the commutator together with the method of coupling.
The small dotted arrows indicate the direction of the current induced before each of
the poles in the convolutions of the coils shown in full lines.
The arrows 1-2, 1-2 and 11-211 shew the direction in which the current is
propagated in the ring armature.
The induced currents of the six parts of the armature are collected by two pairs of
brushes fixed in such a manner that one of the pairs is situated at or over a pole of
one name, and the other pair at or over another pole of the opposite name.

page_text: Fig. 2 illustrates diagrammatically an improved dynamo-machine according to this
invention. A machine with six poles has been chosen by way of example. It has
been stated above that the arrangement of the inductors or field magnets is such
that each field of force forms a magnetic system quite independent of the others and
is closed upon itself by the medium of the iron of the armature.
The dynamo shewn in the drawings comprises three flat or curved field magnets
quite independent of one another, and so disposed as not to offer any consequent
poles. This arrangement thus permits of the pole pieces being of the most suitable
shape for avoiding all loss by the distortion of the lines of force produced.
On making a section m, n (Fig. 2) through the iron of the ring armature, between.
two poles of opposite names belonging to two adjacent electro-magnets it can be
demonstrated by the aid of the improved magnetic explorer (forming the subject of.
a recent application by me for Letters Patent number 2516 of 20 Feb. 1888) that
the intensity of the field of force is practically nil in all the parts of the armature.
situated between two poles of opposite names belonging to two different field magnets
whilst it is at its maximum for all the parts of the iron of the ring armature situated
between the poles of the same field magnet.
Each of the fields of force forms a closed independent circuit and poles of opposite.
names do not divide the circumference into equal parts as heretofore in such machines.
This is a distinguishing feature of this invention.
If the dynamo has six poles and consequently three independent fields of force.
each of these fields of force may comprise an angle of about 120 degrees.
In this manner two pole-pieces of opposite names belonging to two adjacent field
magnets can be brought into very close proximity to each other without the field of
force of each of them ceasing thereby to remain independent and to form a closed
magnetic circuit.
The elementary sections of the ring armature are connected in sets of three each,
in the form of an equilateral triangle as shown in Fig. 1, if the dynamo has three
magnet fields; and in sets of four in the form of a square, if the dynamo has four
magnet fields; and in general in sets of n each when there are n independent
fields.
In each case the poles of opposite names of two adjacent field magnets are merely
arranged symmetrically to each of the radii which divide the circumference into as
many parts as there are magnet fields.
:
In the example shown in Fig. 2, the circumference is divided into three parts by
the radii OX, O X¹, 0 X", and the poles of opposite names A and B, C and D, E
and F, are symmetrical to the straight lines OX, OX¹, 0 X".
This symmetry is necessary in order that the sections of the ring armature con-
nected for quantity may be all at the same time in points where the fields in the
intervening iron have the same intensity.
The induced currents are collected by means of three brushes K. L. M, the outer
ones K and M. being connected for quantity and forming one of the poles, the middle
brush L forming the other pole of the dynamo. The outor brushes are at the most
360°
120° apart, or at if n is the number of magnet fields.
22
In certain cases it is advantageous to employ four brushes as shown in Fig. 1 in
which the brushes are coupled up for quantity, b with b¹ and b, with 6. The former
are situated at a north magnetic pole and the two others at a south pole.
The current circulates in the outer circuit as shown by the arrows 3, and in the
armature as shown by the arrows 1-2, 1-2, 1-211.
All the coils situated in the neutral regions a ß, a¹ ẞ, a" 33" are not traversed by
any current.
In this case the dynamo produces a current having an electro motive force E and
intensity I; but when the brushes are coupled up for electro motive force, that is to
say b is connected to b₁1, and the two others are taken as poles of the dynamo, the
machine will produce at the same speed a current of an electro-motive force of 2 E
and of intensity 1 I.

page_text: This coupling of the brushes for electro-motive force or for quantity, which can be
effected instantaneously by means of a commutator, renders it possible whilst going
at the same speed to either double the electro-motive force by diminishing by half
the output, or to double the latter by diminishing by half the electro-motive force.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a multipolar dynamo electric machine making each magnetic field a field of
force complete in itself, each field including a double pole magnet and a part of the
armature and forming a closed circuit, adjacent poles being of unlike name all round
the armature substantially as described with reference to the drawings.
2. A multipolar dynamo electric machine in which the armature is divided into
magnetic parts or regions separated by neutral or non-magnetic parts or regions, the
number of magnetic regions being equal to half the number of poles in the field
magnet substantially as described.
3. In a dynamo electric machine wherein the fields of force are arranged as
referred to in Claim 1, collecting the induced currents by three or four brushes
whereof one or two are situated at points corresponding to (say) North poles in the
fields of force, and the remainder are situated at points corresponding to (say) south
poles in the fields of force, substantially as described and shewn.
4. In a multipolar dynamo electric machine of the kind referred to in Claim 1 the
combination with three or more brushes of a switch by which the said brushes can
be coupled for electro-motive force or quantity while running substantially as
described.
Dated this 24th day of March 1888.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.