IMPROVEMENTS IN MAGNETO
Year: 1883

page_text: LETTERS PATENT to Alfred de Meuron and Hermann Cuenod Electricians both
of Geneva Switzerland for an Invention of IMPROVEMENTS IN MAGNETO AND
PROVISIONAL SPECIFICATION left by the said Alfred de Meuron and
Hermann Cuenod at the Office of the Commissioners of Patents on the
8th December 1883.
ALFRED DE MEURON and HERMANN CUENOD Electricians both of Geneva
Switzerland "IMPROVEMENTS IN MAGNETO AND DYNAMO ELECTRIC MACHINES
WITH CONTINUOUS CURRENTS
"
The object of our Invention is to remedy the numerous defects in magneto and
dynamo electric continuous current machines intended for the production of electric
light the transmission of motive power or applied to electro metallurgy. A defect
common to all these machines is their great axial speed which causes great wear
and tear and requires great power to work same.
A second defect is the little energy which is obtained from machines which
often might produce much more if it were possible to increase their tangential
speed. The increase of that speed would give a greater efficiency and effec iveness
A third and very serious defect in machines of large size is the production of
sparks on the commutator. Moreover all these machines are generally delicate and
if a brush happens to get displaced or worn out the current may be completely
interrupted.
The difficulties which prevent the construction of good machines are the
following.
The construction of induced armatures of large size with a slow axial-speed
necessitates a powerful field and machines so constructed are costly and cumber-
some. Besides it is only by making use of armatures of a great diameter having
the aforesaid inconveniences that a great tangential speed may be obtained and by
that means a satisfactory quantity of useful work. The sparks on the commutator
proceed from the interruption of a portion of the main circuit at the moment when

page_text: the brushes leave each contact plate and can only be avoided by using a great
Dumber of broad brushes. Hence it is very desirable to arrive at the division of
the armature into a number of coils each receiving a portion of the current in this
manner a machine however powerful could be composed of a certain number of
smaller machines. The machine is thereby rendered less delicate, the contact of a
brush may cease without interruption of the current and the machine continues to
act until the contacts are re-established.
The sparks which are produced at the brushes depend also on the relative
resistance of each section of the induced armature the greater the resistance the
stronger are the sparks for the same current. This resistance is likewise the cause
why the machines become hot and the electro-motive force experiences variations
when a current more or less intense is used with a constant speed of the generator.
Therefore our aim is the reduction of this resistance by diminishing as much as
possible the portions of the armature which are not influenced at all or only to a
small degree.
Our Invention consists of a new arrangement of the electric wires upon the
armature of the magnets of dynamo electric machines so as to obviate the above
mentioned defects and of a magneto or dynamo electric machine provided with an
armature formed as hereafter described.
In principle our armature consists of a drum which may be magnetic or not
fixed on an axis of rotation covered with wires placed longitudinally and parallel
to the axis (as in Gramme's ring or in a coil of Heffner Alteneck) the extremities
of these wires being connected together through wires a b c d each of them forming
a cord of the circumference of the base of the drum and each of thein measuring
a fourth a sixth or any even number of parts of the said circumference instead of
turning backwards and passing inside as in Gramme's ring or turning round the
axis to rejoin the wire diametrically opposite as in Heffner Alteneck's coil.
Fig 3 shews our system of winding Tis the drum on which are shown the
wires 1. 2. 3. 4. placed parallel to its axis. The armature is supposed to be divided
into 6 parts and each wire passes over the bases of the drum through a cord equal
Should the armature be
to the radius viz the sixth part of the circumference.
divided in 4 sections or coils the said cords or connecting wires a. b. c. d for
example would measure one fourth of the circumference. The wires are all
The wire I for
connected together so as to form a single endless conductor.
instance is connected with the wire 6 in such a manner that the end of 1 forms
the beginning of 6 the wire 3 is connected in the same way with 8 and so on, up
to the last which in its turn is connected with the beginning of the first.
We group these conductors in such a manner that they make together a series
of sections which we call coils Each of them thus assumes the form of a conductor
rolled round a rectangle and is connected with the next by a wire ending at the
same time at one of the sections of a commutator. Upon the same end the
collecting brushes in number corresponding to the divisions of the armature establish
the communication between the induced armature and the exterior circuit.
Supposing the armature to consist of 6 or 8 sections the 6 or 8 contacts corre-
sponding to these divisions united 3 or 4 together produces a machine of great
power composed of several weak machines.
transmit but the third or fourth part of the
sparks is reduced in the same proportion.
Thus every pair of brushes has to
whole current and the production of
In fig 3 the wires form 9 coils or sections in connection with 9 metal plates
which form the commutator. Every coil forms a kind of frame surrounding a
portion of the drum which in the drawing is a sixth. Let us follow the wire 4
setting out in the direction of the arrows it follows the exterior surface of the
drum reaches one of its extremities forms the cord a equal to the radius in the
present instance and returns to the other end of the drum thus forming the wire 1
parallel to the axis, passing through the line a¹ it forms the wire 6 through the
cord b the wire 3 through the cord b¹ the wire 8 and so on over the whole exterior
surface of the drum. The circuits thus formed 4-a-1-a or 6-b-3-b¹ and

page_text: so on may also be doubled or multiplied at will as shewn in the fig 3 in forming the
rectangles 4-a-1-a²-4-a-1--a¹ or 6-6-3-62-6-6—3—b¹.
The second part of our Invention refers as before stated to the arrangement of
the machine adapted to this system of armature. We thought it preferable to
make use of a polygonal magnet or electro-magnet having a number of sides equal
to the denominator of the fraction adopted for the windings of the armature. The
angles form the induction poles and the pole pieces are placed within the spaces
extending between the internal angles and the induced drum. In this manner our
field assumes externally the shape of a great polygon whilst inside it has a
cylindrical shape corresponding to (or nearly so) the armature. We fix this
polygonal field as well as the standards of the armature upon a bed plate of cast
iron for example taking care to isolate magnetically the former from it.
Our armature need not have the wires placed parallel to the axis as they may
be arranged radially without any modification in the principle of the sections as
above explained.
The fig 4 shows the arrangement of the wires in this latter case.
The armature
instead of having the shape of a lengthened drum is like a narrow disc of large
diameter and the connecting wires a. b. c. run along the circumference of the disc
whilst the connecting wires a¹. b¹. c¹. and a². b². c². are arranged at a certain distance
from the centre.
The induction wires all situated in the same plain perpendicular to the axis are
indicated by the figures 1. 2. 3. 4. the letters a, b, c, indicate the connection wires
and a, b, c, the wires connecting the coils together. Upon these latter are fixed
the communications with the commutator. The field cannot be (with this
description of armature) of a polygonal shape as in the former case but must be
double thus acting on both surfaces of the disc and composed of magnets parallel
to the axis of rotation. The inductive wires thus run through very energetic lines
of force which emanate from poles of opposite polarity close to one another. The
practical form of this field may vary infinitely and therefore is not represented in
the drawing. Figs 1 and 2 show transverse and longitudinal section of the
machine.
AA are the electro magnets preferably of a rectangular shape but which may be
round or of other suitable form.
PP are the pole pieces to the number of 6 made in such a manner as to envelop
nearly three quarter of the drum and arranged so as to fill the interior angles of
the magnetic polygon.
T is the drum forming the armature. This drum fixed upon an axis is composed
of metal discs K having upon their circumferences an insulating material I upon
which is rolled a magnetic material M (by preference iron wire). Upon this latter
which is employed for strengthening the lines of force of the magnetic field are
coiled the wires according to the method described above and as represented in the
figs 3 and 4. The wires are disposed in a certain number of coils which are
connected with the corresponding sections of the commutator C by the communi-
cations proceeding from the connecting wires a². 62. c2. Upon the commutator C
the brushes or metallic contacts press. In D D is formed the series of adjustable
brush holders fixed to a star F which may turn on a socket fixed to the standard
This system enables us to vary the angle of the brushes screwed up and to change
the direction of the current by turning the whole arrangement one sixth of a
revolution this is advantageous for the preservation of the brushes as the positive
always wear out sooner than the negative. B B in figs 1 and 2 represents a cast
iron frame carrying the standards as well as the polygonal field the latter being
fixed by means of pieces E made of a non-magnetic material,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred de Meuron and Hermann Cuenod in the Patent Office on the
7th June 1884.
ALFRED-DE-MEURON and HERMANN CUENOD both of Geneva Switzerland
IMPROVEMENTS IN MAGNETO AND DYNAMO ELECTRIC MACHINES WITH
CONTINUOUS CURRENTS.
Electricians
The object of our Invention is to remedy the numerous defects in magneto and
dynamo electric continuous current machines intended for the production of
electric light the transmission of motive power applied to electro metallurgy.
A defect common to all these machines is their great axial speed which causes
great wear and tear and requires great. power to work same.
A second defect is the little energy which is obtained from machines which
often might produce much more if it were possible to increase their tangential
speed The increase of that speed would give a greater efficiency and effectiveness.
A third and very serious defect in machines of large size is the production
of sparks on the commutator. Moreover all these machines are generally delicate
and if a brush happens to get displaced or worn out the current may be
completely interrupted.
The difficulties which prevent the construction of good machines are the
following
--
The construction of induced armatures of large size with a slow axial speed
necessitates a powerful field and machines so constructed are costly and cumber-
some. Besides it is only by making use of armatures of a great diameter having
the aforesaid inconveniences that a great tangential speed may be obtained and by
that means a satisfactory quantity of useful work. The sparks on the commutator
proceed from the interruption of a portion of the main circuit at the moment when
the brushes leave each contact plate and can only be avoided by using a great
number of broad brushes. Hence it is very desirable to arrive at the division of
the armature into a number of coils each receiving a portion of the current, in this
manner a machine however powerful could be composed of a certain number of
smaller machines. The machine is thereby rendered less delicate the contact of a
brush may cease without interruption of the current and the machine continues to
act until the contacts are re-established.
The sparks which are produced at the brushes depend also on the relative
resistance of each section of the induced armature the greater the resistance the
stronger are the sparks for the same current. This resistance is likewise the cause
why the machines become hot and the electro-motive force experiences variations
when a current more or less intense is used with a constant speed of the generator.
Therefore our aim is the reduction of this resistance by diminishing as much as
possible the portions of the armature which are not influenced at all or only to a
small degree.
Our Invention consists of a new arrangement of the electric wires upon the
armature of the magnets of dynamo electric machines so as to obviate the above
mentioned defects and of a magneto or dynamo electric machine provided with an
armature formed as hereafter described.
In principle our armature consists of drum which may be magnetic or not fixed
on an axis of rotation covered with wires placed longitudinally and parallel to the
axis (as in Gramme's ring or in a coil of Heffner Alteneck) the extremities of
these wires being connected together through wires a b c d each of them forming a
cord of the circumference of the base of the drum and each of them measuring a

page_text: fourth a sixth or any even number of parts of the said circumference instead of
turning backwards and passing inside as in Gramme's ring or turning round the
axis to rejoin the wire diametrically opposite as in Heffner Alteneck's coil
Fig 3 shews our system of winding. T is the drum on which are shown the
wires 1. 2. 3. 4. placed parallel to its axis. The armature is supposed to be divided
into 6 parts and each wire passes over the bases of the drum through a cord equal
to the radius viz the sixth part of the circumference. Should the armature be
divided in 4 sections or coils the said cords or connecting wires a b c d for example
would measure one fourth of the circumference. The wires are all connected
together so as to form a single endless conductor. The wire 1 for instance is
connected with the wire 6 in such a manner that the end of 1 forms the beginning
of 6 the wire 3 is connected in the same way with 8 and so on up to the last
which in its turn is connected with the beginning of the first.
We group these conductors in such a manner that they make together a series
of section which we call coils. Each of them thus assumes the form of a conductor
rolled round a rectangle and is connected with the next by a wire ending at the
same time at one of the sections of a commutator. Upon the same end the
collecting brushes in number corresponding to the divisions of the armature
establish the communication between the induced armature and the exterior circuit.
Supposing the armature to consist of 6 or 8 sections the 6 or 8 contacts corresponding
to these divisions united 3 or 4 together produces a machine of great power
composed of several weak machines. Thus every pair of brushes has to transmit
but the third or fourth of the whole current and the production of sparks is
reduced in the same proportion.
In fig 3 the wires form 9 coils or sections in connection with 9 metal plates
which form the commutator. Every coil forms a kind of frame surrounding a
portion of the drum which in the drawing is a sixth. Let us follow the wire 4
setting out in the direction of the arrows it follows the exterior surface of the drum
reaches one of its extremities forms the cord a equal to the radius in the present
instance and returns to the other end of the drum thus forming the wire 1 parallel
to the axis passing through the line a¹ it forms the wire 6 through the cord b the
wire 3 through the cord b¹ the wire 8 and so on over the whole exterior surface of
the drum. The circuits thus formed 4-u-1-a' or 6-b-3-6¹ and so on may
also be doubled or multiplied at will as shewn in the fig 3 in forming the rectangles
4-a-1-a-4-a-1-a-or 6-b-3-61-6-6-3-b¹.
The second part of our Invention refers as before stated to the arrangement of
the machine adapted to this system of armature. We thought it preferable to
make use of a polygonal magnet having a number of sides equal to the de-
nominator of the fraction adopted for the windings of the armature. The angles
form the induction poles and the poles pieces are placed within the spaces
extending between the internal angles and the induced drum. In this manner our
field assumes externally the shape of a great polygon whilst inside it has a
cylindrical shape corresponding to (or nearly so) the armature. We fix this
polygonal field as well as the standards of the armature upon a bed plate of cast
iron for example taking care to isolate magnetically the former from it.
Our armature need not have the wires placed parallel to the axis as they may
be arranged radially without any modification in the principle of the sections as
above explained.
The fig 4 shews the arrangement of the wires in this latter case. The armature
instead of having the shape of lengthened drum is like a narrow dise of large
diameter and the connecting wires a bod and a¹ b'c' d' are arranged a certain
distance from the centre
The induction wires all situated in the same plain perpendicular to the axis are
indicated by the figures 1, 2, 3, 4, the letters a b c d indicate the connection wires
and a b c d the wires connecting the coils together upon these latter are fixed
the communications with the commutator.

page_text: The field cannot be with this description of armature of a polygonal shape as in
the former case but must be double thus acting on both surfaces of the disc and
composed of magnets parallel to the axis of rotation. The inductive wires thus run
through very energetic lines of force which emanate from poles of opposite polarity
close to one another The practical form of this may vary infinitely and therefore
is not represented in the drawing. Figs 1 and 2 show transverse and longitudinal
section of the machine.
A A are the electro magnets preferably of a rectangular shape but which may be
round or of other suitable form
PP are the pole pieces to the number of 6 made in such a manner as to envelope
nearly three quarter of the drum and arranged so as to fill the interior angles of
the magnetic polygon.
T is the drum forming the armature. This drum fixed upon an axis is composed
of metal discs K having upon their circumferences an insulating material I upon
which is rolled a magnetic material M (by preference iron wire). Upon this latter
which is employed for strengthening the lines of force of the magnetic field are
coiled the wires according to the method described above and as represented in the
figs 3 and 4.
The wires are disposed in a certain number of coils which are
connected with the corresponding sections of the commutator C by the com-
munications proceeding from the connecting wires a¹ b¹ c' cl' Upon the
commutator C the brushes or metallic contacts press. In D D is formed the series
of adjustable brush holders fixed to a star F which may turn on a socket fixed to
the standard. This system enables us to vary the angle of the brushes screwed up
and to change the direction of the current by turning whole arrangement one
sixth of a revolution this is advantageous for the preservation of the brushes as the
positive always wears out sooner that the negative. Fig 5 shews a modification
of our improved Brush holder
The brushes B touch the commutator C by one of their ends to collect the
current and they are fixed to a pivotted axis the centre a is the centre from which
the curve of the brush B is described. By these means the brushes may wear
without the point of contact with the commutator being displaced. B B in figs 1
and 2 represent a cast iron frame carrying the standards as well as the polygonal
field the latter being fixed by means of pieces E made of a non-magnetic material.
Having thus described and ascertained the nature and object of my said
Invention and the means whereby the same may be carried into practical effect I
would remark in conclusion that what I claim as my Invention and desire to
secure by the hereinbefore in part recited letters patent is
The improvements in magneto and dynamo electric machines with continuous
currents substantially as set forth.
In Witness whereof we the said Alfred-de-Meuron and Hermann Cuenod have
hereunto set our hands and seals this Third day of June in the year of our Lord One
thousand eight hundred and eighty four