An Improved Construction of Alternate Current Dynamo Electric Motors.
Year: 1891

page_text: Date of Application, 12th Jan., 1891
Complete Specification Left, 9th Oct., 1891-Accepted, 21st Nov., 1891
PROVISIONAL SPECIFICATION.
An Improved Construction of Alternate Current Dynamo Electric
Motors.
We, MAURICE HUTIN, of No. 16 Rue de St. Petersburg, Paris, France, and
MAURICE LEBLANC, of No. 63 Allee du Jardin Anglais, Raimey, Seine et Oise,
France, Engineers, do hereby declare the nature of this invention to be as
follows :-
This invention relates to an improved construction of alternate current dynamo
electric motors, which consists mainly of a fixed ring and a revolving drum within
the said ring, each of which is covered with two distinct electric circuits.
Each circuit of the ring is formed of 2 n bobbins similar to those of the Gramme
ring arranged at equal distances round the periphery.
The direction of coiling is changed in passing from one bobbin to the next, in
one and he same circuit, so that a current sent through the circuit generates in the
rings 2 n poles which are alternately positive and negative.
The two circuits of the ring are arranged symetrically relatively to each other.
Each circuit of the drum is formed of 2 n bars of copper arranged regularly
along the periphery, parallel with the drum's axis, and connected alternately at
opposite ends.
These bars might be replaced by the same number of bobbins either of the
Gramme or the Siemens kind. The terminals of the coils are respectively
connected to one of two conducting discs fixed on the drum axis, on which bear
fixed brushes. There may be included in each circuit a variable external
resistance, which is placed between the fixed brushes that bear upon the discs.
Thus if into the two fixed circuits two alternating currents having the same
phase be sent so that the impulses of the one is displaced th of the phase
relatively to the other, the two moveable circuits being made to include suitable
resistances, a motor couple will be developed upon the drum axis which will be
independent of the speed of rotation.
For obtaining these two alternating currents of the same mean intensity but of
different phases, we employ either of the following arrangements.
According to one arrangement the two fixed circuits are mounted in a shunt of
the main circuit, but each one is intercepted by a condenser of suitable capacity
different from the capacity of the other condenser.
The two moveable circuits include separate rheostats and the resistances of which
These two
are always equal, but which vary with the speed of the machine.
rheostats can be actuated by one and the same mechanism.
According to the second arrangement, the two fixed circuits are arranged in
series upon the main circuit, but the current is made to pass through them in
contrary directions, and between a point of the ingoing current and a point of
the outgoing current is interposed a condenser of suitable capacity on a shunt.
.The two moveable circuits are made to include two rheostats of variable but
equal resistance as in the first case.
With either of the above arrangements, if an alternating current be sent through
the main circuit, it will be divided into two alternating currents of equal mean
intensity but which will be displaced to the extent of one fourth of the phase.
When the machine is to be supplied with a current from a transformer it will be
advantageous to proceed in the following manner. Two transformers of exactly
the same power are employed. The secondary circuit of the one will supply the
first fixed circuit of the machine, and the secondary circuit of the other will supply

page_text: the secondary fixed circuit of the machine. The two primary circuits will be
provided either with two or a single condenser as previously described.
In constructing machines according to the above described methods, there are
mounted upon the armature axis a number of sheet iron discs closely side by side
but insulated from each other and having their peripheries formed with dove-tail or
under cut notches, so as to form together a series of longitudinal grooves.
ebonite sheathing is interposed between them and the axis, and they are held
together by collars on the axis and screws.
An
Through the grooves pass a series of copper bolts, which constitute the moveable
circuits, and which are insulated from the iron drum by an ebonite sheathing.
They are coupled up at alternate ends by insulated copper plates.
In
The terminals of these circuits are connected respectively to two pairs of insulated
conducting rings fixed, respectively at each end of the drum on the axis.
grooves in these rings are mounted conducting collars to which are fixed conducting
bars which hold them stationary and connect them to screw terminals, between
which are situated the before mentioned rheostats.
The fixed ring of the machine is in like manner built up of a number of annular
thin sheet iron plates, formed with notches both at the inner and the outer circum-
ference, being insulated from each other by paper. They are tied together by
insulated screw bolts passing through them and secured to end cheeks. Spaces are
formed at intervals between the plates for ventilation, for which purpose washers
are threaded on the bolts. The circuit wires are coiled round the inner and outer
grooves of the ring formed by the notches of the plates. The ring is carried by a
bronze bracket at each end, fixed to the shaft bearings.
In place of the above described construction of armature, a ring- or cylinder-
shaped one may be employed on which the circuits may be, coiled like a Siemens
armature.
According to a modified construction, the fixed circuits are constructed in a
similar manner to the revolving circuits of the previous arrangement, but instead of
making the conductors of copper bolts, they are made of more or less thick wire.
There are three conducting discs with three brushes at one end of the axis, for
supplying the currents, these discs being connected to three wires passing through
the axis and connected respectively one with the ingoing wire of the first circuit,
the second with the ingoing wire of the second circuit, and the third to the outgoing
wires of both circuits.
For the before mentioned condensers may be employed other known apparatus
having like properties, such as accumulators and thermo-electric batteries.
Dated this 12th day of January 1890.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
An Improved Construction of Alternate Current Dynamo Electric
Motors.
We, MAURICE HUTIN, of No. 16 Rue de St. Petersburg, Paris, France, and
MAURICE LEBLANC, of No. 63 Allee du Jardin Anglais, Raimey, Seine et Oise,
France, Engineers, 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 :-
Our invention relates to an improved construction of alternate current dynamo
electric motors, as we shall describe referring to the accompanying drawings.
As shewn diagrammatically by Fig. 1 a motor according to our invention
consists of a stationary ring A, forming the field, within which revolves a drum or
armature B, both the ring and the drum being provided with two distinct electric
circuits. The ring A is wound with 2 n coils viz. n coils a₁ a, &c. up to an and

page_text: cons aa &c. up to a n, like those of a Gramme ring arranged regularly around
the periphery.
The direction of winding of each coil is opposite to that of the next in order in
the same circuit, so that the current passing through the coils in each circuit
develops 2 n alternating poles. The entering and leaving conductors for the one
circuit are indicated by e and s, and those for the other by e and s'. The drum
carries 2 n bars of copper, viz. n bars &c. up to bn and a bars b', b', &c. up
ton, connected as indicated diagrammatically by Fig. 2, e and s indicating the
entering and leaving conductors for this circuit. Instead of these bars, coils like
those of Gramme or Siemens' armatures may be used. The 4 conductors e and s
and e and s are connected to discs fixed on the axis of the drum with stationary
rubbers bearing on them, these being connected through suitable resistances to the
stationary ring circuits. When these circuits receive two alternating currents of
equal period, but the one in a phase one quarter of a wave length behind the other,
a motor couple is developed causing the drum to revolve independent of its speed
of rotation. In order to determine this difference of phase of two currents of
equal mean intensity, either of two arrangements may be adopted as indicated
diagrammatically by Figs. 3 and 4 respectively. The two ring circuits es and e¹ sl
are in shunts from the line the one having a condenser C in its circuit. The
two drum circuits are closed on two separate rheostats R. and R' of resistance
always equal but both made to vary with the speed of rotation. As shewn in Fig. 4,
the two ring circuits es e' s' are in the line but opposite in direction, and a condenser C
is introduced in a connection from between the points e el and a point in the return
line 1. In this case the drum circuits are arranged as in Fig 3. When the
condenser is of suitable capacity, any alternating current conveyed by the line
becomes divided into two alternating currents of equal intensity but with a
difference of phase of of a wave length. When the current is to be supplied by
a transformer it is of advantage to employ two transformers, one supplying each of
the ring circuits from its secondary coil, whilst the primary coils are connected to
the line through condensers as described with reference to Figs. 3 and 4. Such
being the principle on which the machine operates, we shall now describe its
construction as shewn by Fig. 7 which is a longitudinal section, and Fig. 8 which
is an end view, half of the end frame being removed to shew some of the parts
beyond. On the shaft X are fixed side by side, insulated from each other, a
number of thin iron discs of the shape shewn by Fig. 5. They are all insulated
from the shaft by an interposed sleeve M of ebonite or other suitable insulating
material, and are closely pressed together between nuts Ee screwed on the shaft.
They are traversed by a number of copper bolts A B. which form parts of the
drum circuits and which are insulated by sleeves of ebonite or the like.
The bolts A B are connected to one another as indicated in Fig. 2 by insulated
copper segments C for the one circuit and C' for the other, and the first and last bolts
of the two circuits are connected to the 4 insulated grooved metal rings R, R, R, R,
fixed on the shaft. In the grooves of the rings R rest 4 stationary metal
rings P, P, PP, connected respectively to 4 conductors L₁ L, L, L, leading to
suitable terminals between which are arranged the necessary rheostats which, in
order to avoid confusion, are not shewn.
1
2
The stationary ring or field consists of a set of rings S of thin iron plate cut to
the shape shewn by Fig. 6; they are insulated from each other by thin paper and
are pressed together by two end rings D D traversed by bolts EF these parts
being suitably insulated by rings f, washers m and sleeves g of insulating material.
Several void spaces are left for ventilation between the plates which are there
kept apart by insulating rings K. In the notches of the ring are lodged coils H
wound like those of a Gramme ring, and embracing the end rings DD; these coils
form the two circuits of the ring, their leading wires being connected to the 4 posts
shewn in Fig. 8. The ring is carried by two gun metal frames G, one at each end
of the ring and pressed against it by nuts on the bolts E. The frames G are fitted
on the shaft bearings and prevented from turning by pins I screwed into the

page_text: bearings. There are openings through the frames G to allow passage for the
conductors L and for air to circulate through the machine.
Besides the parts described, the machine has a suitable framing with bearings
for the shaft and pullies, with the required rheostats and condensers, all of
ordinary kind.
For the drum described may be substituted a ring like the outer ring but
smaller, or a Siemens drum.
In any case the coils are equal in number to those of
the outer ring and form two circuits connected as described to ring conductors.
The rheostats should be so arranged that the resistances introduced in the drum
circuits shall be greatest at the start, and that they shall decrease as the speed
increases, this condition being necessary to render the motor couple independent of
the speed. It may be noted that the period of the induced alternating current
depends on the speed of rotation, and is least at the start. Further, as is well
known, a conductor of large section presents to the passage of an alternating
current a resistance which is greater the shorter the period, and this is especially
the case with conductors of iron. It follows therefore that if we substitute an iron
cylinder for the induced circuits of the machine above described, the currents
induced in the mass would encounter a resistance the greater the less the speed.
Under these conditions the motive force would to a great extent be rendered
constant. But it is more simple to fix the iron cylinder by casting it with the
framing as shewn, in longitudinal section by Fig. 9 and in plan by Fig. 10. In this
machine, the inductor Y is similar to the drum of the machine previously described,
but, instead of employing the copper bolts, wires may be used of section suited to
the current, these being wound and connected as before. As shewn in Figs. 9 and 10,
the rings R and brushes P are arranged outside; there are 3 of these rings from
which conductors lead through the shaft X, the first and second to enter the first
and second drum circuits, respectively, and the third to lead from both of these.
It may be mentioned that instead of condensers, accumulators and thermo electric
batteries might be used.
Having thus described the nature of this invention and in what manner the same
is to be performed, we declare that what we claim is :-
An alternate current dynamo electric motor wherein are combined an inductor or
field consisting of two equal currents and so arranged that each pole resulting from
the one is at equal distance from two successive poles of the other, a condenser or
pair of condensers arranged to produce a difference of phase of a quarter of a
wave in the currents for the two circuits-an armature consisting also of two
circuits arranged like those of the field-and two rheostats for the armature
circuits having their resistances varied but always equal to one another-all
substantially as described.
Dated this 9th day of October 1891.
ABEL & IMRAY,
Agents for the Applicants.