Improvements in Continuous Current Dynamos, either for Generating or for Receiving Electric Currents.
Year: 1893

page_text: Date of Application, 4th Dec., 1893
Complete Specification Left, 28th Aug., 1894-Accepted, 29th Sept., 1894
Improvements in Continuous Current Dynamos, either for Generating
or for Receiving Electric Currents.
We, MAURICE HUTIN, of No. 46 Rue Caumartin, Paris, Engineer, and
MAURICE LEBLANC, of No. 63 Allee du Jardin Anglais, Le Raincy, Seine and
Oise, France, Engineer, do hereby declare the nature of this invention to be as
follows:-
Our invention has for its object a construction of continuous current machines in
which the connections shall be as simple as in alternate current dynamos, and
in which the inconveniences inherent to weak polar pieces are avoided and the
commutator is reduced to the smallest possible dimensions.
For this purpose the dynamo is constructed either with a fixed armature while
the field magnets revolve within this armature, or the reverse arrangement may be
employed. We will describe the invention as applied to the first mentioned
arrangement.
The armature is composed of sheet metal rings placed side by side, but insulated
from each other, the rings being secured together by two lateral bronze cheeks
connected together by insulated transverse bolts.
Near the inner edge of this ring-shaped armature are formed transverse perfora-
tions for the reception of the circuit wires or rods constituting the winding. This
winding is made of the Siemens multipolar kind, for which purpose there are passed
through the said perforations, firstly a tubular rod and secondly a concentric
insulated solid rod passing through the former, the ends of separate groups of which
rods are respectively connected in series at their extremities. The electromotive
forces produced in these two circuits are of equal valve, but the connections may be
so arranged that the second circuit represents, at each moment, an electromotive
force that is shifted half a period relatively to the other.
1th
2n
If the interval separating two poles be divided into n equal parts, and each
point of division be made to constitute the one terminal of each of the above named
circuits, there will be 2 circuits which will contain 2 n electromotive forces shifted
relatively to each other of the entire period. If we consider any one of these
circuits, then every time that the field magnets have turned to an extent corre-
sponding to the interval separating two poles of the same sign, the circuit will
experience identically the same conditions of induction. If the machine has
2 K poles, these periods will be reproduced K times during every revolution, and
the machine will be in the same conditions as a continuous current Gramme machine
having 2 n sections and with a commutator having 2 a plates, but revolving K times
as fast and the dimensions of the commutator will be as much smaller relatively
to the machine as this number K is greater.
In addition, the commutator instead of being placed upon the machine, can be
disconnected therefrom, forming a separate apparatus driven by a small synchronous
motor of the kind described in the Specification to our Patent 13765, which would
be adjusted to revolve K times as fast as the generator. Or the commutator might
be driven from the dynamo at the required speed by means of toothed gearing or
pitch wheels and chains. In the said arrangement the terminals of each winding of
the armature are each connected to a corresponding plate of the commutator
through one of a series of contact rings fixed upon and revolving with the comma-
tator axis, with which ring a fixed brush is in contact that is connected by a lead to
the corresponding terminal of the winding, the other terminal being connected

page_text: through a second brush with a second ring, and each ring being connected by a wire
with the corresponding plate of the armature.
The terminals of the sections of the windings are so coupled up that there
are only as many contact rings and brushes required as there are sections in the
armature.
The commutator may be made to rotate and the commutator brushes fixed, or the
reverse arrangement may be employed.
The revolving central field magnet or inductor consists of an iron ring from which
project radially a number of poles, each of which carries a bobbin or winding. On
each side face of this inductor is fixed a bronze ring, which rings are connected
together by means of bronze bolts or rods arranged at equal distances apart all
round the circumference of the inductor, and passing transversely through both the
polar extensions thereof and the spaces between these. By this means there are
constituted at the extremities of the polar extensions a series of deadening circuits
having very little electrical resistance, and that will allow the free passage of the
magnetic flux from the inductor to the armature but which will energetically oppose
all variations in the said flux, and will also prevent the formation of the extra
current, so detrimental to the machine, which ensues on the accidental sudden
breaking of a circuit, owing to the sudden discharge of the potential energy of the
machine.
Dated this 4th day of December 1893.
ABEL & IMRAY,
Agents for Applicants.
UITICALIVA
Improvements in Continuous Current Dynamos, either for Generating
or for Receiving Electric Currents.
We, MAURICE HUTIN, of No. 46 Rue Caumartin, Paris, Engineer, and
MAURICE LEBLANC, of No. 63 Allee du Jardin Anglais, Le Raincy, Seine and
Oise, France, 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 :-
In continuous current dynamo generators, the number of plates of the com-
mutator is equal to the number of sections of the armature or induced part. This
number may be very considerable, as in the multipolar machines.
These machines require as many brushes as there are poles constituting the
magnetic field, unless special connections are made necessitating the use of only two
brushes. In consequence, the commutator requires to be of large dimensions and
becomes of difficult construction, or else the number of poles of the magnetic field
has to be considerably limited.
By means of our invention, we are enabled to make the number of the collector
plates independent of the number of separate sections of the armature, by
imparting to the commutator a speed differing from that of the dynamo. The
commutator is consequently separated from the machine, and its speed of rotation
is determined as follows.
Referring to the diagram Fig. 1 of the accompanying drawings, if N, S, N, S₁....
NS, be the developed 2k poles of a multipolar dynamo machine, we divide the
interval between two consecutive poles of the same sign into 2n equal
parts, 1, 21
2n being the circuits subjected to the induction of the
poles N S₁; 12 22
2n, the circuits subjected to the induction of the
poles N, S, 1₂ k 22 k
2 n those submitted to the induction of
the poles N, S₂k.
2
It will be seen that all the circuits having the same number are subjected to the
same induction; it is therefore possible to connect together all the circuits of

page_text: the same number, thus forming 2n circuits in which the currents will be regularly
shifted period relatively to each other.
In imparting either to the poles or to the circuits a motion in the direction of the
arrow, it will be seen that the several circuits will be subject to the same induction
when a pole having a certain index takes the place of the pole of the same sign
and of the immediately preceding index; as there are 2 k poles this condition will
be repeated times for each revolution of the armature.
There are consequently 2 n circuits with currents regularly shifted by period ;
the different circuits and the different poles will assume the same relative
position times during one revolution.
In an ordinary bi-polar dynamo there are also 2 a currents regularly shifted, but
the different circuits and the different poles will only assume the same relative
position once during a revolution. In connecting the 2n circuits to an ordinary
commutator of 2 plates, and in causing this to rotate times as fast as the
dynamo with 2k poles, the condition of things will be the same as if there were a
commutator having times the number of plates.
Instead of only considering a single circuit occupying a certain position relatively
to the poles, we can take two superposed circuits as indicated at Fig. 2, where the
one circuit is shewn by a full line, and the other by a dotted line.
the circuits which are subject to the same induction as shown in the figure, we shall
By grouping
have 2n distinct circuits with currents shifted. period.
The action of the commutator will be as in the preceding example, in giving it a
speed times as great as that of the armature of the machine.
This arrangement will offer greater facilities of construction than the preceding
one.
We have only considered the relative motion of the poles and of the induced
sections; consequently either the armature or the magnetic field may be rotated, the
other part being stationary, with the same result. If the armature rotates, the
extremities of the 2 n circuits will make contact with 2 n insulated rings mounted
on the shaft of the dynamo. The shifted currents will be collected on these rings
by means of as many brushes, connected respectively with other brushes in contact
with rings mounted on the shaft of the separate commutator.
These will be connected respectively with the plates of the commutator.
If the armature is fixed, the 2 n conductors are connected directly to the brushes
of the separate commutator.
The rotation of the separate commutator is effected either by means of suitable
transmission gear from the dynamo, or by an auxiliary synchronous motor, of any
suitable known construction such as that described in the Specification to our
Patent No. 13765 of 1892 adapted to rotate & times as fast as the dynamo.
The separation of the dynamo from the commutator enables the latter to have
any speed proportional to that of the dynamo imparted to it. In certain cases it
may be advantageous to give it a less speed than the dynamo. Assuming the
dynamo to be a bipolar machine the speed of which is very considerable, then if
the commutator is mounted on the shaft of the dynamo, the communications would
take place under unfavourable conditions, owing to the high speed. Under these
conditions we provide a separate commutator provided with plates the number of
which is a multiple of the number of sections of the dynamo.
The plates corresponding to one section are arranged symetrically on the
commutator, and are all connected together. The current is taken up by two
brushes and the speed of rotation of the commutator is equal to the speed of the
dynamo divided by the number of plates of the commutator corresponding to one
section of the armature.
We will describe by way of example the application of the above described
construction of separate commutator to a dynamo machine with rotating field
magnets as shewn at Fig. 3, & being equal to 16, and there being 32 poles on the
wheel m, which poles are alternately of opposite sign.
The fixed armature is formed of ring a composed of sheet metal plates placed

page_text: closely side by side and insulated from each other, as shewn more clearly in the
enlarged part elevation and cross section at Figs. 4 and 4^.
The space between two successive poles of the same sign is divided into eight
equal parts, that is to say, the factor n before mentioned is equal to 4; the induced
circuits are formed by insulated bolts passing through the sheet metal rings, and
for producing the superposed windings shewn diagrammatically at Fig. 2, a second
circuit is formed by surrounding the bolts by a tube f insulated therefrom and
from the sheet iron armature ring.
These tubes and bolts are connected respectively at their ends by external
aunular plates t'as shewn at Fig. 4*, the connections being such as to form the
circuits shewn at Fig. 2. The eight conductors passing from the machine are
connected to the brushes g of the separate commutator, shewn in end view, front
view, and plan respectively at Figs. 5, 6 and 7. These brushes bear upon rings h
connected to the commutator r on the one hand, and on the other hand to the
sections of the synchronous motors which may be of the kind described in the
Specification to our Patent No. 13765 of 1892. The brushes bearing upon
the commutator r will collect the current produced by the machine.
Instead of rotating the commutator and keeping the brushes fixed, the reverse
arrangement may be adopted, the brushes being rotated by the synchronous motor
or by gearing from the dynamo, while the commutator is fixed.
Referring to Figs. 3, 4 and 4ª, n are the bobbins of the poles of the field magnet,
p. o. is, a "deadening circuit" such as we have described in the Specification to
our application No. 23309 of 1893.
Fig. 8 shews a diagram of the circuits connecting the dynamo with the brushes g
of the separate commutator, and the rings with the commutator and auxiliary
inotor.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In continuous current dynamo machines, constructing the commutator separate
from the dynamo and imparting thereto a speed of rotation different from that of
the rotating part of the dynamo, such speed being determined as herein described,
and the rotation of either the commutator or of the brushes being effected either
by a separate synchronous motor or by transmission gear from the dynamo machine,
substantially as described.
2. The construction of dynamo-machine with separate commutator, and with
armature winding composed of two sets of conductors the one arranged concentrically
within the other, which is of tubular form, as herein described with reference to
the drawings.
Dated this 27th day of August 1894.
ABEL & IMRAY,
Agents for the Applicants.