IMPROVEMENTS IN DYNAMO-ELECTRIC AND MAGNETO-ELECTRIC MACHINES
Year: 1876

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
DYNAMO-ELECTRIC AND MAGNETO-ELECTRIC MACHINES." A. communication
from abroad by Dieudonné François Joseph Lontin, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 19th August 1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN DYNAMO-ELECTRIC AND MAGNETO-ELECTRO
MACHINES."
The object of this Invention is to obviate the defects existing in dynamo-electric
machines now in use, and to ensure the working of such machines for a greater length
of time.
One of these defects is the great heat developed in the induced coils or helices
which is due to the too great frequency of the induction in these coils. To avoid
this inconvenience it is only necessary to multiply the number of these parts in
order to diminish or avoid entirely the development of heat therein.
Another defect is the rapid destruction of the commutators in powerful machines
by the oxidising heat produced by the sparks emitted thereat, which are due to
three causes,-1st, the current proper; 2nd, the extra current; 3rd, static electricity.
The current proper must be retained, since it is the object of the machine to pro-
duce it, but the extra current may be made to disappear by the use of condensers.
Static electricity is produced but slightly if in the construction of the coils of these
machines the use of two perfect insulators is avoided.
In order to avoid the oxidizing effect of the electricity on the commutators in the
presence of air, it is only necessary to enclose the commutators in a bath of non-
drying oil. The oxidizing action being only produced in large machines this pre-
caution is unnecessary in small ones, more especially as the electricity may be suffi-

page_text: ciently distributed over the commutators to avoid this oxidizing action by increasing
the number of commutators according to the degree of distribution desired.
Figure 1 shows how these results may be attained. Pis an iron wheel or pinion
provided with arms and mounted on an axis or shaft to which rotary motion may
be imparted if mounted in bearings. Each arm of the wheel has coils of insulated
conducting wire upon it, and thus forms a source of induced electricity if the wheel
which I call the induction wheel, be rotated in front of one or several electro-
magnets into which a portion of the electricity so generated is made to flow to
strengthen the residual magnetism of their cores, by which this electricity is in the
first place produced. This Invention therefore consists in the employment and ap-
plication of this induction wheel or any inodifications thereof. For example, when
rotated in front of a permanent steel magnet, a magneto-electric machine is formed.
The magnets may be of any known form. I reserve the right of applying one or
several of these induction wheels on the same shaft and placing them opposite one
or several series, each composed of one or several electro-magnets. I also reserve
the right for collecting the electricity, of using commutators or collectors or contact
rings, either in oil boxes or in air, and either fixed directly to the machine or apart
therefrom. This being premised, I will now describe the action of these dynamo-
electric machines, for which purpose I will refer to Figure 1, which represents-a
machine composed as above mentioned of an induction wheel P capable of rotating
in front of the poles of an electro-magnet A, A¹. On the wheel being rotated the
following effect is produced:-When one arm of the wheel passes a pole of the
electro-magnet tho residual magnetism of this electro-magnet reacts so as to produce
an induction current in the coil on the arm of the induction wheel, and similarly on
the passage of the other coils. If a part of this electricity so generated be made
uniform in direction by means of a commutator or a collector and made to flow
into the wire of the electro-magnet A, A', it is evident that the electro-magnet
will become very powerful, and the quantity of electricity generated will go on
increasing. As in this case a part only of the electricity produced has been
used to excite the electro-magnet the remainder is free to be utilized for out-
side work. If the currents to be used are required to be invariable in direction,
it is only necessary to use a commutator or a collector, otherwise they may be
collected by friction or contact rings.
A second modification also shown in Figure 1 consists in two induction wheels
on the same shaft (they would in the case illustrated be made shorter) of which one
is applied solely to react on the electro-magnet, and the other to furnish the current
to be used for outside work. These two wheels may be of variable relative
dimensions.
If the currents are required to be of invarying direction I employ the col-
lectors as follows:-For the sake of simplicity I will confine the explanation to one
wheel only, the other being similar. In the first place, the wire of the induction
wheel should be so placed that being wound in the same direction on each arm of
the wheel the final extremities of each of the wires shall be connected to the initial
extremities of the following coils so as to form a completely closed circuit. The
result is that all the arms of the wheel which are approaching a pole of the electro-
magnet are inversely electrified to the arms which are receding from the said polc.
A metal strip or rubber is placed opposite this pole of the electro-magnet to collect
the electricity generated at the instant that its polarity becomes reversed, a similar
arrangement being applied to the other pole of the electro-magnet to form the second
pole of the machine. It will be readily understood that if the arms of the wheel
are sufficiently numerous the current will thus be absolutely continuous. On the
other hand, even with a small number of arms the current would be absolutely con-
tinuous but would vary in power. Such is the manner of employing a collector.
If it be desired to use commutators which are more convenient for certain pur-
poses the necessary number of commutators are placed on the shaft, and to each
commutator are attached the extremities of the wire of a single coil, or two alternato
coils at most. If the quantity of electricity is insufficient for the purpose intended,

page_text: it is only necessary to connect to the poles or rubbers of an adjacent commutator so
that the electricity will be accumulated in the same direction and in tension. .More-
over the quantity and tension may be modified by simply changing the numbers of
the wires used for the induced coils.
In a special machine in which the currents are not made uniform in direction, for
a powerful electric light for instance, although the number of arms on the wheels
is optional, it is preferable to have 8 or 10 arms. Instead of one series of electro-
magnets I would use two, each of four electro-magnets, one of the series of electro-
magnets being placed in front of a wheel having 8 arms, each pole perfectly equi-
distant. The second series of electro-magnets would be placed in the presence of a
second induction wheel having 10 arms, which necessarily implies that although in
the presence the one of the other, in this series there would be two arms of the wheel
which will not be in presence of the electro-magnet pole. In this induction wheel
if the coils are connected so as to form a closed circuit, electricity always of same
name may be taken from this coil by means of a commutator at the instant when it
is no longer influenced. These currents after being made uniform in direction will
serve to excite the electro-magnet. The second series of this machine which would
produce alternate currents, is collected by contact or friction rings attached at a
break in the closed circuit. It is evident that the electro-magnets of this second
series would be excited by the same electricity as the electro-magnets of the first
series. The result will be a machine producing the electric light with alternate
currents, whilst completely preserving the commutators used to return the currents
made uniform in direction into the assemblage of electro-magnets.
If the numbers above mentioned of electro-magnets, or of arms for the induction
wheel be used, a very simple means of constructing the electro-magnets would be to
couple them two and two upon the same connecting or cross bar as represented in
Figure 2.
I will mention as another modification of the machine two induction wheels on
the same shaft, in presence of a single series of electro-magnets wide enough to cover
the length of the two wheels together. Suppose for a moment these two wheels to
have cach 8 arms, and that there are 8 electro-magnet poles, the whole equidistant,
I collect the alternate currents as above mentioned by means of a friction or contact
ring. For the currents of uniform direction the arrangement is as follows:-Join
upon the shaft 8 commutators, each with the extremities of the wire of one arm of
the induction wheel. This commutator conveys the current into the wire of one of
the limbs of one of the electro-magnets. By this division of the currents of uniform
direction I avoid all serious wear of the commutators. If the machine is of very
large size the number of commutators may be increased by putting several wires
together on the induction coils, each wire in communication with a special commu-
tator conveying the current into a part only of the wire of one of the electro-
magnet limbs. These wires might be connected together at the ingress and egross
ends of each coil. I reserve the right to the form of this electro-magnet containing
several poels mounted upon one and the same platinum connecting bar.
- This machine may be utilized for all purposes in science and the arts for which
electricity is used. Small machines may be constructed for therapeutic purposes,
whether with continuous or interrupted currents. The machines may also be ar-
ranged as magneto-electric (see Figure 1) or dynamo-electric machines.
As a modification of the arrangement, Figure 2, the following arrangement might
be employed by preference, see Figure 3, consisting in part of Figuro 2 cut through
its centre along the line -, perpendicular to its axis. One induction wheel P
only is retained, the one with the friction or contact rings a¹¹; this wheel would
turn in presence of electro-magnets c, c¹, which may be in symmetrical and super-
posed series, each of several electro-magnets on the same connecting bar, and being
equal in length to the length of the induction wheel. The other part of the machine
dispensed with would be replaced by the arrangement, Figure 1, in its entirety;
the wheels would be arranged on a single shaft, or, better still, arranged on two
shafts connected by a sleeve m.. The two series of electro-magnets also will be

page_text: independent, which if necessary would admit of forming two machines producing
different results.
This union of Figure 2 in part with Figure 3 will produce the following effects :-
Under the influence of the residual magnetism of the electro-magnets A, A¹, a current
is produced in the short coils H of the induction wheel; this current multiplies
itself at each passage before the poles of the electros, and it is connected by means of
the commutator a and made to flow into the electros A, A¹, and is thus considerably
reinforced. These electros react on the medium coils H¹, which send by means of
the commutator a the powerful current which they produce into the series of electro-
magnets C, O², superposed or otherwise, ordinary or multiple (see hereafter). A strong
current will thus be produced in the coils H under the influence of the one which
excites C, C, it will be collected, by means of friction or contact rings a¹¹ or com-
mutators, according as it will be utilized for the production of the electric light, or
for any other purpose. The use of ordinary or multiple electro-magnets in simple
or superposed series is optional, according to the power of the machines and the
application intended. I call ordinary electro-magnets those with one or two
branches or limbs; multiple electro-magnets those with several branches or limbs
The use of several
on the same connecting bar or base, as above mentioned.
ordinary electro-magnets close together constitutes a multiple electro-magnet, which
I may use with good results.
I will continue the explanation of some parts of my machine previously described,
and constructed in view of a new modification, which I apply to all dynamo-electric
machines. Upon this modification is based another grant of Letters Patent, dated
February 8th, 1875, No. 473, for obtaining metals by the employment of dynamo-
electric machines thus modified.
As described in the Specification of this Patent, the object of this new modification
is to employ directly the whole of the electricity produced for the magnetization of
the electro-magnets of the dynamo-electric machine. Under these circumstances the
resistance to rotation increases to such an extent that after a few moments it would
be impossible to overcome it. It is then only necessary to make a break, and place
in the circuit (by means of an automatic commutator L, whose function is to close
at will the circuit upon itself) the special apparatus, according to the results to be
obtained. The action of the machine then becomes normal. Before the stoppage of
the machine the automatic commutator L (Figure 2a) has for its function to close the
circuit on the electro-magnets of the dynamo-electric machine. The work done
may be various, and may be any to which electricity is applied in science and
the arts.
As indicated in the Patent No. 473, 1875, before referred to, in order to use a
dynamo-electro machine thus transformed into a dynamo-chemical machine, it is
only necessary to make a break at any point in the wires of the machine, and to
place there the voltameters on which it is desired to act. Under the name of
dynamo-chemical machine I believe I have made it completely understood, both as
regards the Patent No. 473, 1875, as well as the present one, that I include under
this name all systems of dynamo-electric machines in which all the electricity pro-
duced is thrown into the electro-magnet or magnets of the machines, whether these
machines are made as above described or otherwise.
What I desire to claim the exclusive right of is a different manner of employing
the electric current generated in dynamo-electric machines, whether there be one or
Beveral induced parts, or whether there be one or several electro-magnets. If in
any dynamo-electric machine the whole of the current produced be returned into
the electro-magnets, and if in the path of the current any voltameters be interposed,
what I term a dynamo-chemical machine will be formed, of which I have specified
and claimed the chemical applications in Patent No. 473, 1875. Similarly, if only
a part of the current is so returned, if this part of the current is employed in the
same way as that above described, that is to say, by interposing in the path of the
current the voltameters on which it is desired to operate.
By the term voltameter is here meant a vessel in which chemical decomposition

page_text: is effected, such as the production of metals, electroplating with gold, silver, nickel,
copper, and other similar operations with any metals capable of being deposited by
cheinical decomposition; also, the production of gas, and any other chemical
operation.
I also reserve all the applications which may result from this manner of employing
the electricity of dynamo-electric machines by interposing in the circuit the appa-
ratus for obtaining the desired results; thus if I interpose in the circuit of a
dynamo-chemical machine any machines containing electro-magnets, or even one or
several electro-magnets (such as electric sorters, electric brakes, electric motors,
electric steering gear, &c.), I obtain a different result, which from chemical becomes
magnetic. A machine thus employed I would call dynamo-magnetogene; this
machine if used for electric lighting I would call dynamo-photogene; employed for
heating, I would call it dynamo-calorigene. Each machine would be so constructed
as to produce the desired results, the principle remaining however always the same.
I reserve therefore all the applications which may be made of this new mode of
employing electricity with any sort of dynamo-electric machine. The construction
of the machines remains the same as above described and shewn in the annexed
Drawings. This new arrangement of returning the whole of the electricity pro-
duced into the electro-magnet or magnets of the machine being applicable to all
dynamo-electric machines, I reserve the right absolutely to so supply it, whether the
machines have one or several induction wheels or coils or are constructed with a
single series of induction coils or wheels, as shown in Figure 3.
"
"
88
It has been stated above that "the wheels would be arranged on a single shaft,
for, better still, arranged on two shafts connected by a sleeve m. The series of
electro-magnets also will be independent, which if necessary would admit of
"forming two machines producing different results."
It has also been stated "that this machine would have but a single induction
"wheel ;" and, again, reference has been made to the "right of placing one or several
induction wheels opposite one or several series of one or several electro-magnets."
Figure 3 shows the two machines insulated the one from the other. The one has
a single series of coils or induction wheel, and the other has two series. Figures 2ª
and 2b also show the induction wheel turning opposite the poles of electro-magnets
G, G¹, which may, in accordance with what has been stated above, be of several
kinds, according to the end in view; they may be ordinary or multiple, and in
single or superposed series.
I reserve the right of applying in all kinds of dynamo-electric machines the
principle of sending all the electricity produced by one or more series of coils or
induction wheels to the electro-magnets of the dynamo-electric machine; of intro-
ducing in a break in the circuit the apparatus in which the desired chemical or
magnetic result is to be produced, this principle having been laid down in the Patent
No. 473, 1875; and the construction of machines with one series of coils or induction
wheel having been already described herein.
I would add that I effect a sensible improvement in all dynamo-electric and
dynamo-chemical machines by employing as rubbers against the collectors, com-
mutators, or friction rings, clips formed of thin metal blades of a single width, or
split into the form of a comb, or made in separate pieces placed side by side. These
thin metal blades are placed near one another, with or without a space between,
and fixed to a rigid or flexible support, and so that they may be readily removed
from their support to shift or change them. The position of these blades relatively
to the collectors or commutators, &c., is quite arbitrary. I reserve the exclusive
right to employ these rubbers, which have the advantage of flexibility, and take the
current well in all dynamo-electric or dynamo-chemical machines.
The manner in which the current is produced in the ciols of the induction wheel
remains the same as described at the commencement of the Specification. These
currents are uniform or alternate in direction according as the machines are
provided with collectors, commutators, or friction rings, and the purpose to which
the machines are applied.

page_text: I will now describe some further modifications which may be made in the
arrangement of the parts of the machine in order to reduce the power of the sparks
which may be emitted at the collectors of the dynamo-electric, dynamo-chemical, or
magneto-electric machines. To this end I arrange as previously described on the
same shaft A. (Figures 4, 4ª, and 5) of steel or preferably of iron, several induction
wheels P constructed as previously of arms or cores D of soft iron fixed on the
boss P, as shewn in Figure 4º, and each carrying a coil of covered copper wire like
those of an electro-magnet. The form of these cores may be varied according to the
result desired.
The prosent improvement is 'designed to multiply the parts, and it consists
especially in the position of each induction wheel relatively to its neighbour, this
position being such that there will be but one coil in any one lino parallel to the
direction of the shaft A, see Figures 4, 5, 5; Figure 5ª represents delineated on a
plano surface several induction wheels P, P, P, P, mounted on the same shaft A.
The coils D are shown cylindrical, but may be of other form as before mentioned.
The coils of the different wheels are in different longitudinal planes passing through
the axis of the shaft, so that no two are in the same plane as above mentioned.
The grouping of the coils amongst themselves and the taking of the currents by
the rubbers a, u', are the same as previously described. The current is taken on
the line of the poles (Figure 4) or magnetic axis X, X1, forming a neutral line which
is the moment of no current for the two coils or series of coils which are opposite
the two contrary poles; the electricity produced is taken at the instant it changes
polarity by placing opposite the poles a metal blade or rubber a, a¹. In these
machines this magnetic axis is direct, since all the parts which constitute it are on
the same straight line entirely of iron and therefore magnetizable, and of opposite
polarity at the extremities and form the neutral line which is the moment of
no current in the coils which are changing polarity. The apparent position of the
rubbers a, a¹, may be different to that shown, but in that case the connecting loops
or wires are carried round in a circular direction to a position more convenient for
adjusting the rubbers, but in reality the currents' are taken always on the line of
the poles or magnetic axis x¹, a¹, x², a¹.
The induction wheels may thus be shortly described as consisting of induction
coils or helices, whose cores are arms of soft iron fixed directly on a boss of iron,
and the whole forming a magnetizable mass which receives in all its parts the
magnetic influence of the inductive action of the inductor magnets or electro-
magnets.
"
The grouping of the copper of the coils amongst themselves and the taking of the
currents has been effected by Mr. Worms de Romilly in 1866, in his magneto-
electric machine with a closed ring, and by the adoption of part of his Invention I
obtain continuous currents unvarying in direction.
To more fully explain the arrangement I employ I will quote so much from the
description of Mr. Worms de Romilly's Invention as relates to this grouping and
taking of the currents. "It would be sufficient to pass before the poles a scrics of
"wires separated from one another, and which communicato at each end with a
"stationary conducting wire which touches them one after the other at the moment
they are passing the pole, in order to have the current produced successively on
"the passage of each separate wire before the inductor pole without the possibility
"of any of this current being lost. I now suppose that each separate wire will be
"connected to its neighbour, so that the current produced in the one shall
" be in the same [direction as and a continuation of that produced in the other,
" thus forming a sort of battery in which each wire would be an element. To
"increase the tension each wire would be formed into a coil wound round a core."
To resume I connect among themselves all the coils of the induction wheels, and it
is at the extremities of each suitably arranged "as simple insulated contacts placed
on the axis of the cylinder" that I take the currents they produce, and which follow
one another in the same direction. As before mentioned the currents are taken on
the line of the opposite poles or magnetic axis x1, x¹³, x³, x²
{t
"

page_text: Figure 4 represents a single induction wheel P mounted and placed opposite one
or several ordinary or superposed electro-magnets. The line ¹, x, is the magnetic'
axis or direct line of the poles, the wheel being made entirely of iron. I reserve
the right of placing on the same shaft (Figure 5) as required, one or any indefinite
number of induction wheels having any desired number of coils, one or several
collectors being provided according to the effect desired. The boss on which the
cores of the coils are fixed may be solid or hollow and with or without iron discs or
washers placed within.
The narrow wheels grouped, as in Figure 5, present greater facilities in the
arrangement and working of the machine.
The connection of the cores of the coils directly to the same boss or base made
entirely of iron constituting a well defined feature, as above explained, all arrange-
ments attaining the same result by changing the position of the cores relatively to
the shaft are intended to be included herein if they have for result to place the
cores of the induction coils around the same boss made entirely of iron, thus forming
a single magnetizable mass. For example, a disc of iron on which are fixed a
number of iron cores covered with wire like electro-magnets; but not the same
cores and coils upon a cylinder or disc made of an unmagnetizable material. Such
an arrangement is in fact found in certain magneto-electric machines, such as the
"Alliance" and "Breguet" machines which are therefore quite different in principle
to mine. I have also sought to diminish the rapidity with which each coil is
magnetized and demagnetized in order to diminish the spark emitted at the
collectors, which result I have attained by extending the poles of the electro-magnets
so as to surround the induction wheel or wheels, either partly or wholly.
Figures 4 and 5 show these extensions R¹, R', which only partially surround the
wheel in the Figures, but which it is easy to see might be sufficiently prolonged to
completely surround the induction wheels. The induction coils or helixes furnishing
the current to the rubbers a, a¹, at the moment of no current (magnetic axis) in the
coils or helixes which are changing polarity, the spark is consequently considerably
diminished and theoretically should cease entirely, I reserve the right to use these
curved polar extensions applied, either to magnets or electro-magnets in magneto or
dynamo-electric machines whenever this extension covers several independent coils,
each having a special core. These extensions may be of different forms, in certain
cases they would be tubular or flat, according to the kind of machine and position
of the induction coils they surround. These polar extensions applied to the
inductor magnets or electro-magnets never having been used in magneto or
dynamo-electric machines having induction coils which are individuably separable,
and each have a special core of iron, I reserve the right of so applying them in all
cases when they may be applicable. I of course except machines having Siemen's
armatures, such as the Wilde and the Ladd machines, and machines such as those
of Worms de Romilly, and of Gramme. In these machines these extensions are
indispensible, and the principle is distinct from that which I describe, having in one
complete rotation but a single induction armature. The induction wheels of this
Invention may in any case be so disposed that I may apply either the system
with two independent circuits, or that of sending the whole of the electricity
produced to the electro-magnets with a single circuit by employing one or several
collectors.
The copper covering the induction coils and electro-magnets of the different
machines may be modified according to the purpose in view, and may be in the
form of wire of various metals, covered or not, and fine or coarse, or it may be in
the form of metallic ribbons or strips placed edgewise, or flat covering, if desired,
the whole length of the induction coils, and the branches of the electro-magnets
with metallic ribbon. The wires may therefore be flat, round, or square, and of
different metals covered or not.
The electro-magnets E, E¹, may be of any known form; Figures 4 and 5 show
them flat, but they may be round, tubular, concentric, or in bundles of iron wire;
they may be combined in all the ways above mentioned, that is to say, ordinary or

page_text: multiple, in single or superposed series. A superposed system comprises two
ordinary or multiple electro-magnets placed the one above the other, their poles
being in contact or separated by a metallic or other substance. The cores of the
coils of the induction wheels may be solid or hollow, divided or not, or composed of
bundles of iron wire.
In all cases the electro-magnets of the different kinds of dynamo-electric and
dynamo-chemical machines may be replaced by permanent steel magnets, the
machines thus becoming magneto-electric. An electro-magnet magnetized to
saturation is always more powerful than a permanent inagnet of the same weight,
and it is therefore advantageous to use electro-inagnets magnetized by the machine
itself, as they give better results with less weight.
All these machines yield continuous currents, that is to say, if the same direction,
but by employing the arrangement before described they will produce alternato
currents which are preferable for the electric light. The polar extensions, above
mentioned, may be applied to other machines having multiple coils, such as the
"Alliance" and "Breguet" machines. The discs or plates of these machines are in
wood or other insulating material, and have induction coils either in one or several
series.
Figures 6 and 7 show how these machines, which are magneto-electric, that is to
say, have steel magnet inductors, may, say be transformed into dynamo-electric
machines, that is to say have electro-magnet inductors, with the optional use of the
polar extensions R, R¹, of flat form as above mentioned. The effect of using these
extensions being to diminish or avoid the emission of sparks at the collectors, and
to augment the magnetizing surfaces, I employ the said extensions in all machines
having multiple coils individually independent of one another. These machines,
thus modified, might be capable, according as they are provided with one or several
collectors, of receiving the whole or part of the current with a single circuit in accord-
ance with the Patent No. 473, 1875. Although these machines differ entirely
in principle from the Lontin machines I reserve the right of applying to them
these modifications and improvements.
The induction wheel, herein described, may serve as an electric motor, whether
it be placed between the poles of permanent or electro-magnets suitably disposed.
It has a great motive power, and may be actuated by a battery or by another
dynamo-electric machine. It may be specially constructed to act as an electric
motor, but any machine may be arranged to serve either as an electric motor or as
a dynamo-electric machine. I therefore reserve the right to apply this induction
wheel to all the purposes for which it is suitable.
These dynamo-electric machines, in which the whole of the current is thrown into
the inducing electro-magnets, that is to say, having a single circuit, may be used as
powerful brakes, whilst retaining their suitability for the purpose of which they were
constructed if desired. When the circuit is open they turn without presenting any
resistance, but as soon as the circuit is closed by the slightest contact, they oppose a
considerable resistance to rotation. A machine weighing 100 kilogrammes, for
example, requires but the strength of a child to work it when the circuit is open,
but will arrest 6 to 8 horse power when the circuit is closed, and this without any
complication of mechanical parts, nor the use of batteries. The machine itself im-
mediately generates the magnetism necessary to produce this powerful effect. I
reserve the right to this novel application as a brake in machines of any kind.
This magnetic brake may be constructed and applied in various ways.
All these details constitute important modifications and improvements applicable
to all kinds of magneto-electric and dynamo-electric machines, and I therefore
reserve the absolute right to so apply and use them.
I also reserve the right to the following modifications in the induction wheels to
produce alternate currents :-I use a small dynamo-electric machine to maintain the
magnetization of the inductor electro-magnets, but as shown in Figure 8, the
electro-magnets A, A, are placed opposite the extremities of a shaft furnished with
two or more induction wheels without coils, which turn in front of their poles.

page_text: These electro-magnets, and these wheels, are at a distance from each other, and on
the part of the shaft between them I coil the necessary quantity of wire to
develop electricity therein. In this case the wheels being unprovided with coils are
of very simple construction, and the arrangement of the wires is excessively easy,
and exempt from any liability to be disarranged. It is of course necessary that the
poles of the electro-magnets, between which these wheels turn, should be similar
for each of them, for, it will be readily understood, the magnetization of the shaft
must be in the direction of its length.
I may also invert the action of the apparatus by making the rotary shaft the
inductor, and having a series of induced parts B, B, Figure 9, arranged around in
a circle, at which the currents may be taken without using any collector or friction
ring, as shown in Figure 10. In Figure 9 the central shaft is covered with wire,
the cross N, N, made of iron serving as the polar extremity and as induction wheel.
I. consider it advisable, in this particular form, to mount parallel on the shaft four
electro-magnets P, which add their action by alternation of polarity with the
central shaft, that is to say, that at the side where the north pole of the rotary
shaft is, will be placed the south poles of these alternated and parallel electro-
magnets.
It is unnecessary to remark that the number of arms on the pinions and that of
the electro-magnets alternated therewith is optional, moreover I find it convenient
to effect the magnetization of these machines by a special machine similar to those
described at the commencement of this Specification. I may also employ this
modification of the wheel as shown in Figure 11, in which the wheel is exactly
similar to that in Figure 8, but instead of making it turn opposite two double poles
only, I make it turn opposite a great number of electro-magnet inductors placed
outside the circumference. In this particular case the poles will be alternately
dissimilar, so that one pole of one of these inductors will be always between two
poles dissimilar thereto. Thus it will be readily seen by the drawing that in 1/8th
of a revolution of the wheel, its induction by magnetization is reversed, and con-
sequently in a complete revolution there are eight reversals, and I thus obtain
alternate currents. If on this wheel I place several wires, I can take several
separate currents by means of a sufficient number of friction rings placed on the
shaft, and thus produce several electric lights with a single coil of several wires.
This machine admitting of the use of cylindrical electro-magnets its cost is greatly
reduced.
Each cylindrical electro-magnet is provided at its extremity with a pole of iron
fixed on the cores of the electro-magnet in such manner as to leave a certain
amount of play, which admits of their being brought as close together as may be
desired to regulate the effect of the magnetization, and thus give the machine its
maximum effect without fear of the parts being deranged even by wear, in the
event of which the parts may be easily readjusted to rectify any derangement caused
by wear.
I have stated above that I use a special machine producing currents uniform in
direction to effect the magnetization of these machines, but I would remark that I
may also magnetize them by any other source of electricity producing invariable
currents, such as a battery, or a Lontin, Romilly, Gramme, Wilde, Siemen's
Alliance, or Clarke machine in which the currents are made uniform.
Although generally less preferable I reserve the power to make uniform part of
the currents produced in these machines to furnish magnetism to the machine
itself, thereby dispensing in this case with the use of a special machine for the
purpose of magnetization.
I will describe further improvements in the construction of dynamo and
magneto electric machines:-As above described the dynamo-electric machines are
composed essentially of a large number of coils fixed on cores or arms of soft iron
around a boss, which I have called an induction wheel, and which turns in front of
the poles of one or several electro-magnets. This induction wheel may be in one
-piece, but in practice I prefer to fix each arm on a disc or cylinder which may be of

page_text: any metal, but preferably iron. Each carries a coil of copper wire, but as during
the rotation these coils tend to fly off, I have avoided this by making the cores of
these coils b, b, of conical form with the base outwards, as shown Figure 12. Thus
the coils cannot fly off, and moreover the induction is more easily effected which
admits of the speed of the machine being reduced. To facilitate the passage of the
wires which connect the coils I provide a groove a between them on the discs, as
shown Figure 12.
To strengthen the induction wheels, whether they act as inductors or are induced,
I form the base of each arm of dovetail form as in Figure 13.
When in certain cases the size of the electro-magnet inductors becomes con-
siderable, I construct them of several independent cores A, A, A, Figure 14, covered
with wire in the ordinary way, the similar poles being fixed to the same base S,
and having a single polar piece P. I have also made certain modifications in the
rubbers which take the current. When the rubbers are a little worn the point
which takes the current becomes modified in form, so that the machine no longer
yields its maximum effect. To enable them to be replaced an adjusted more casily,
I arrange them as follows, and shown in Figure 15:-I fix on the frame of the
machine a metal block B insulated by wood or hardened india-rubber; to this
block is hinged an arm D bent into the form of the arc of a circle so as to partly
surround the collector at a distance therefrom. On this arc is mounted a slide F
carrying at its lower part the rubbing point or blade. The slide F may be fixed in
its proper position on the arc by means of a set screw, and it may be adjusted
during the working of the machine. A spring R maintains the necessary contact
of the rubbers with the collector.
I will now describe a new rubber for larger machines which avoids the wear
above referred to, and reduces the resistance due to friction. It consists of a
toothed wheel, each tooth of which is so mounted as to be perfectly insulated; each
of these teeth represents a plate of the old form of collector, and consequently a
point at which the current is taken. A second wheel, entirely metallic, gears with
the collecting wheel. It is movable with its axis in a quadrant-shaped support,
which admits of the whole being placed in the best position relative to the first
wheel to obtain the maximum effect of the machine.
Figures 16, 17, 18, 19, represent this arrangement, Figure 16, showing a face
view, Figure 17, a plan, Figure 18, a transverse section of the collecting wheel,
and Figure 19, a section on line 1, 2, Figure 18. a, a, are two metal plates
forming the body of the collecting wheel A, and having each an internal circular
groove b, in which are successively inserted the metal teeth c which are notched
laterally at d, Figure 20, to receive the wooden keys e, Figure 21, so shaped as to
fix and lock the teeth in place, and at same time completely insulate them, the
teeth and keys being introduced at an opening made for the purpose in the
plates a, a. The last key introduced locks the whole, and is itself fastened with a
bolt. represents the connections of the wires with the teeth; g, g', are brass
quadrants concentric with wheel A insulated from the bars h, h. On these
quadrants are fitted the adjustable slides i, i¹, which carry the upper and lower
metal wheels j, j', and by shifting which these wheels may be placed in the proper
position.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Alexander Melville Clark, in the Great Seal Patent Office on the 17th
February 1877.
"
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex, 50
Patent Agent. IMPROVEMENTS IN DYNAMO-ELECTRIC AND MAGNETO-ELECTRIC
MACHINES." A communication from abroad by Dieudonné François Joseph Lontin,
of Paris, France.

page_text: machines now in use, and to ensure the working of such machines for a greater
length of time.
One of these defects is the great heat developed in the induced coils or helices,
which is due to the too great frequency of the induction in these coils. To
avoid this inconvenience it is only necessary to multiply the number of these parts,
in order to diminish or avoid entirely the development of heat theroin.
Another defect is the rapid destruction of the commutators in powerful machines
by the oxidising heat produced by the sparks emitted therein, which are due to
three causes, 1st, the current proper; 2nd, the extra current; 3rd, static
electricity.
The current proper must be retained, since it is the object of the machine to
produce it, but the extra current may be made to disappear by the use of condensers.
Static electricity is produced but slightly if in the construction of the coils of
these machines the use of too perfect insulators is avoided.
In order to avoid the oxidising effect of the electricity on the commutators in
the presence of air it is only necessary to enclose the cominutators in a bath of non-
drying oil. The oxidising action being only produced in large machines, this pre-
caution is unnecessary in small ones, more especially as the electricity may bo
sufficiently distributed over the commutators to avoid this oxidising action by
increasing the number of cominutators according to the degree of distribution desired.
Figure 1 of the accompanying Drawings shows how these results may be attained.
P is an iron wheel in the form of a pinion provided with arms, and mounted
on au axis or shaft to which rotary motion may be imparted when mounted in
bearings. Fach arm of the wheel has coils of insulating conducting wiro upon it,
and thus forins a source of induced electricity if the wheel, which I call tho
induction wheel, be rotated in front of one or several electro-magnets, into which a
portion of the electricity so generated is made to flow to strengthen the residual
magnetism of their cores by which this electricity is in the first place produced.
I, therefore, clnim the use of this induction wheel, and of the various modifications
and applications thereof. Thus, suppose it to be rotated in front of a permanent
steel magnet, a magneto-electric machine is formed. The magnets may be of any
known form. I reserve the right of applying one or several of these induction
wheels on the same shaft, and placing them opposite one or several series, cach com-
posed of one or several electro-magnets. I reserve the right for collecting the
electricity of using commutators or collectors or contact rings either in oil boxes
or in air, and either fixed directly to the machine or apart therefrom. This being
premised, I will now describe the action of these dynamo-electric machines, for
which purpose I will refer to Figure 1, which represents a machine composed, as
above mentioned, of an induction wheel P capable of rotating in front of the poles
of an electro-magnet A, A'. On the wheel being rotated the following effect is
produced-When one arm of the wheel passes a pole of the electro-magnet the
residual magnetism of this latter reacts, so as to produce an induction current in
the coil on the arm of the induction wheel, and similarly on the passage of the
other arms or coils. If a part of this electricity so generated be made uniformn in
direction by means of a commutator or collector, and made to flow into the wire of
the electro-magnet A, A¹, it is evident that the electro-magnet will become very
powerful, and the quantity of electricity generated will go on increasing. As in
this case a part only of the electricity produced has been used to excite the electro-
magnet the remainder is free to be utilized for outside work. If the currents to
be used are required to be invariable in direction it is only necessary to use a
commutator or a collector, otherwise the electricity may be collected by friction or
contact rings.
A second modification, also shown in Figure 1, consists in two induction wheels
on the same shaft (they would in the case illustrated be made shorter), of which
one is applied solely to react on the electro-magnet, and the other to furnish the
current to be used for outside work; these two wheels may be of variable
relative dimensions.

page_text: If the currents are required to be of unvarying direction I arrange the
collectors as follows:-For the sake of simplicity I will confine the expla-
nation to one wheel only, the other being similar. In the first place, the wire
of the induction wheel should be so placed that being wound in the same
direction on each arm of the induction wheel the final extremities of each of the
wires shall be connected to the initial extremities of the following coils, so as to
form a completely closed circuit. The result is that all the arms of the wheel,
which are approaching a pole of the electro-magnet, are inversely felectrified to
the arms which are receding from the said pole. A metal strip or rubber is placed
opposito this pole of the electro-magnet to collect the electricity generated at the
instant that its polarity becomes reversed, a similar arrangement being applied to
the other pole of the electro-magnet to form the second pole of the machine. It
will thus be readily understood that if the arms of the wheel are sufficiently
numerous the current will thus be absolutely continuous, and even with a small
number of arms the current would be absolutely continuous, but would vary in
power. Such is the manner of employing a collector.
If it be desired to use commutators, which are more convenient for certain pur-
poses, the necessary number of commutators are placed on the shaft, and to each
commutator are attached the extremitics of the wire of a single coil, or two alternate
coils at most. If the quantity of electricity is insufficient for the purpose intended
it is only necessary to connect with the poles or rubbers of an adjacent com-
mutator, so that the electricity will be accumulated in the same direction, and for
tension. Moreover, the quantity and tension may be modified by merely changing
the number of the wires used for the induced coils.
In a machine in which the currents are not made uniform in direction for a
powerful electric light, for instance, although the number of arms on the wheel is
optional, it is preferable to have 8 or 10 arms. Instead of one series of electro-
magnets two would be used, each of four electro-magnets, one of these series of
electro-magnets being placed in front of a wheel having 8 arms, each pole perfectly
equidistant. The second series of electro-magnets would be placed in the presence
of a second induction wheel having 10 arms, which necessarily implies that although
in presence the one of the other in this series there would be two arms of the
wheel which would not be in presence of the electro-magnet pole. In this induction
wheel, if the coils are connected so as to form a closed circuit, electricity always of same
name may be taken from this coil by means of a commutator at the instant when
it is no longer influenced. These currents after being made uniform in direction
will serve to excite the electro-magnet. The second series of this machine, which
would produce alternate currents, is collected by contact or friction rings attached
at a break in the closed circuit. It is evident that the electro-magnets of this
second series would be excited by the same electricity as the electro-magnets of the
first series. The result will be a machine producing the electric light with alternate
currents, whilst completely preserving the commutators used to return the currents
made uniform in direction into the assemblage of electro-magnets.
If the numbers above mentioned of electro-magnets or of arms for the induction
wheel be used, a very simple means of constructing the electro-magnets would be to
couple them two-and-two upon the same connecting or cross bar, as represented in
Figure 2.
Another modification of the machine may be mentioned; two induction wheels
on the same shaft, in presence of a single series of electro-magnets wide enough to
cover the length of the two wheels together. Suppose for a moment these two
wheels to have each 8 arms, and that there are 8 electro-magnet poles, the whole
equidistant, the alternate currents are collected as above mentioned by means of
a friction or contact ring.
For the currents of uniform direction the arrangement is as follows:-Join upon the
shaft 8 commutators, each with the extremities of the wire of one arm of the induction
wheel. This commutator conveys the current into the wire of one of the limbs of
one of the electro-magnets. By this division of the currents of uniform direction

page_text: all serious wear of the commutators is avoided. If the machine is of very large size
the number of commutators may be increased by putting several wires together on
the induction coils, each wire in communication with a special commutator conveying
the current into a part only of the wire of one of the electro-magnet limbs. These
wires might be connected together at the egress and ingress ends of each coil. I
reserve the right to this form of electro-magnet, containing several poles mounted
upon one and the same platinum connecting bar.
This machine may be utilized for all purposes in science and the arts for which
electricity is used. Small machines may be constructed for therapentic purposes,
whether with continuous or interrupted currents. The machines may also be
arranged as magneto-electric (see Figure 1a) or as dynamo-electric machines.
As a modification of the arrangement Figure 2, the following arrangement might
be employed by preference (see Figure 3), consisting in part of Figure 2 cut through
its centre along the line a¹, a, perpendicular to its axis. One induction wheel P
only is retained, the one with the friction or contact rings a¹¹. This wheel would
turn in presence of electro-magnets c, c¹, which may be in symmetrical and
superposed series, each of several electro-magnets on the same connecting bar, and
being equal in length to the length of the induction wheel. The other part of the
machine dispensed with would be replaced by the arrangement Figure 1 in its
entirety; the wheels would be arranged on a single shaft, or better still, arranged
on two shafts connected by a sleeve m. The two series of electro-magnets also will
be independent, which if necessary would admit of forming two machines producing
different results.
This union of Figure 2 in part with Figure 3 will produce the following effects :-
Under the influence of the residual magnetism of the electro-magnets A, A¹, a
current is produced in the short coils H of the induction wheel. This current
multiplies itself at each passage before the poles of the electro-magnets, and it is
collected by means of the commutator a, and made to flow into the electro-magnets
A, A¹, and is thus considerably reinforced. These electro-magnets react on the
medium size coils H¹, which send by means of the commutator a the powerful
current which they produce into the series of electro-magnets C, C¹, superposed or
otherwise, ordinary or multiple (see bereafter). A strong current will thus be
produced in the coils H under the influence of the one which excites C, C¹. It will
be collected by means of friction or contact rings all or commutators, according as
it will be utilized for the production of the electric light or for any other purpose.
The use of ordinary or multiple electro-magnets in simple or superposed series is
optional, according to the power of the machines and the application intended.
By ordinary electro-magnets, I mean those with one or two branches or limbs;
by multiple electro-magnets, those with several branches or limbs on the same
connecting bar or base as above mentioned. The use of several ordinary electro-
magnets close together constitutes a multiple electro-magnet, which may be used
with good results.
I will continue the explanation of some parts of the machine previously described
and constructed in view of a new modification which is applicable to all dynamo-
electric machines. Upon this modification is based another grant of Letters Patent,
dated February 8th, 1875, No. 473, for obtaining metals by the employment of
dynamo-electric machines thus modified. As described in the Specification of this
Patent, the object of this new modification is to employ directly the whole of the
electricity produced for the magnetization of the electro-magnets of the dynamo-
electric machine. Under these circumstances the resistance to rotation increases to
such an extent that after a few moments it would be impossible to overcome it. It
is then only necessary to make a break and place in the circuit (by means of an
automatic commutator L, whose function is to close at will the circuit upon
itself) the special apparatus according to the results to be obtained. The action of
the machine then becomes normal. Before the stoppage of the machine, the
automatic commutator L (Figure 2a) has for its function to close the circuit on the
electro-magnets of the dynamo-alectric machine. The work done may be various,

page_text: and may,
as previously stated, be any to which electricity is applied in science and
the arts.
As indicated in the Patent No. 473, 1875, before referred to, in order to use a
dynamo-electric machine thus transformed into a dynamo-chemical machine, it is
only necessary to make a break at any point on the wires of the machine and to
place there the voltameters on which it is desired to act. Under the name of
dynamo-chemical machines it will be understood is included, both as regards the
Patent No. 473, 1875, as well as the present one, all systems of dynamo-electric
machines in which the whole of the electricity produced is returned or thrown into
the electro-magnet or magnets of the machines, whether these machines are made
as above described or otherwise, the novelty herein claimed consisting in the new
way of employing the electric current generated in dynamo-electric machines,
whether there be one or several induced parts, or whether there be one or several
olectro-magnets. If in any dynamo-electric machine the whole of the current
produced be returned into the electro-magnets, and if in the path of the current
any voltameters bo interposed, what is here termed a dynamo-chemical machine
will be formed, the chemical applications of which are specified and claimed in the
Patent No. 473, 1875, before referred to; and similarly will be deemed an infringe-
ment of the same any machine in which only a part of the current is so returned if
this part of the current is employed in the same way as that above described, that
is to say, by interposing in the path of the current the voltameters on which it is
desired to operate.
By the term "voltameter" is here meant a vessel in which chemical decomposition
is effected, such as the production of metals, electroplating with gold, silver, nickel,
copper, and other similar operations with any metals capable of being deposited by
chemical decomposition. Also the production of gas, and any other chemical
operation.
The Invention also comprises all other applications which may result from this
manner of employing the clectricity of dynamo-electric machines by interposing in
the circuit the apparatus for obtaining the desired results. Thus, if in the circuit
of a dynamo-chemical machine any machines be interposed containing electro-
magnets, or even one or several electro-magnets (such as electric sorters, electric
breaks, electric motors, electric steering gear, &c.), a different result is obtained,
which from chemical becomes magnetic. A. machine thus employed would bo
termed dynamo-magnetogene; this machine if used for electric lighting would be
termed dynamo-photogene; and if for heating would be termed dynamo-calorigene.
Each machine would be so constructed as to produce the desired results, the principal
remaining however always the same. I therefore reserve all the applications which
may result from this new mode of employing electricity with any sort of dynamo-
electric machine. The construction of the machine remains the same as above
described and shown in the annexed Drawings. This new arrangement of
returning the whole of the electricity produced into the electro-magnet or magnets
of the machine being applicable to all dynamo-electric machines. The right is
reserved absolutely to so apply it, whether the machines have one or several
induction wheels or coils, or are constructed with a single scries of induction coils
or wheels, as shown in Figure 3.
"
"
It has been stated above that "the wheels would be arranged on a single shaft,
or better still, arranged on two shafts connected by a sleeve m. The series of
electro-magnets also will be independent, which if necessary would admit of
forming two machines producing different results."
It has also been stated that this machine would have but a single induction
wheel; and again, reference has been inade to the right of placing one or several
induction wheels opposite one or several scries of one or several electro-magnets.
Figure 3 shows the two machines insulated the one from the other. The one has
a single series of coils or induction wheels, and the other has two series; Figures &
2 and 2b also show the induction wheel turning opposite the poles of electro-
magnets G, G¹, which may in accordance with what has been stated above be of

page_text: several kinds according to the end in view; they may be ordinary or multiple, and
in single or superposed scries.
I reserve the right of applying in all kinds of dynamo-electric machines the
principle of sending all the electricity produced by one or more series of coils or
induction wheels to the electro-magnets of the dynamo-electric machine, of intro-
ducing in a break of the circuit the apparatus in which the desired chemical or
magnetic result is to be produced, the principle having been laid down in Patent
No. 473, 1875, and the construction of machines with one series of coils or induc-
tion wheels having been already described herein.
A sensible improvement in all dynamo-electric and dynamo-chemical machines
is effected by employing as rubbers against the collectors, commutators, or friction
rings, clips formed of thin metal blades of a single width or split into the form of
a comb, or made in separate pieces placed side by side. These thin metal blades.
are placed near one another, with or without a space between, and fixed to a rigid
or flexible support, and so that they may be readily removed from their support to
shift or change them. The position of these blades relatively to the collectors,
commutators, &c., is quito arbitrary. I reserve the exclusive right to employ theso
rubbers, which have the advantage of flexibility and take the current well, in all
dynamo-electric or dynamo-chemical machines.
The manner in which the current is produced in the coils of the induction wheel
remains the same as described at the commencement of this Specification. These
currents are uniform or alternate in direction according as the machines are pro-
vided with collectors, commutators, or friction rings, and the purpose to which the
machines are applied.
The Invention further relates to some modifications which may be made in the
arrangement of the parts of the machine in order to reduce the power of the sparks
which may be emitted at the collectors of the dynamo-electric, dynamo-chemical,
or magneto-electric machines. To this end there is arranged, as previously
described, on the same shaft A (Figures 4, 4ª, and 5), of steel, or preferably of iron,
several induction wheels I, constructed as previously of arms or cores D of soft
iron fixed on the boss P, as shown in Figure 4, and each carrying a coil of
covered copper wire, like those of an electro-magnet. The form of these cores may
be varied according to the result desired.
The present improvement is designed to multiply the parts, and it consists
especially in the position of each induction wheel relatively to its neighbour, this
position being such that there will be but one coil in any one line parallel to the.
direction of the shaft A, see Figures 4, 5, 5º. Figure 5ª represents delineated on
a plane surface the peripheries of several induction wheels P, P, P, P, mounted on
the same shaft A. The coils D are shown cylindrical, but may he of other form,
as above mentioned.. The coils of the different wheels are in different longitudinal
planes passing through the axis of the shaft, so that no two are in the same plane,
as above mentioned, although they are equidistant in the circular direction.
The grouping of the coils amongst themselves, and the taking of the currents by
the rubbers a, a, are the same as previously described. The current is taken on
the line of the poles (Figure 4) or magnetic axis X', X', forming a neutral line,
which is the moment of no current for the two coils or series of coils which are
opposite the two contrary poles; the electricity produced is taken at the instant
it changes polarity by placing opposite the poles a metal blade or rubber a, a¹.
In these machines this inagnetic axis is direct, since all the parts which constituto
it are in the same straight line, entirely of iron, and therefore magnetizable, and of
opposite polarity at the extremities, and form the neutral line, which is tho
moment of no current in the coils which are changing polarity. The apparent
position of the rubbers a, a, may be different to that shown, but in that case the
connecting loops or wires are carried round in a circular direction to a position
more convenient for adjusting the rubbers, but in reality the currents are taken.
always on the line of the poles or magnet axis x, x², x², x².
The induction wheels may thus be shortly described as consisting of induction

page_text: coils or helices whose cores are arms of soft iron fixed directly on a boss of iron,
and the whole forming a magnetizable mass, which receives in all its parts the
magnetic influence of the inductive action of the inductor magnets or electro-
magnets (Figure 4ª).
The grouping of the copper of the coils amongst themselves, and the taking of
the currents, has been effected by Mr. Worms de Romilly, in 1866, in his magneto-
electric machine with a closed ring, and by the adoption of part of his Invention
continuous currents unvarying in direction are obtained.
$5
ΓΕ
"5
To more fully explain the arrangement employed I will quote so much from
the description of Mr. Worms de Romilly's Invention as relates to this grouping
and taking of the currents:-"It would be sufficient to pass before the poles a
"series of wires, separated from one another and communicating at each end with a
stationary conducting wire, touching them one after the other at the moment they
are passing the pole, in order to have the current produced successively on the
passage of each separate wire before the inductor pole without the possibility of any
"of this current being lost. I now suppose that each separate wire will be con-
"nected to its neighbour, so that the current produced in the one shall be in the
same direction as, and a continuation of, that produced in the other, thus forming
'a sort of battery, in which each wire would be an element. To increase the
"tonsional effect each wire would be formed into a coil wound round a core." To
resume, all the coils of the induction wheels are connected among themselves, and
it is at the extremities of each suitably arranged as "simple insulated contacts
placed on the axis of the cylinder" that the currents they produce are taken, and
which follow one another in the same direction. As before mentioned, the currents
are taken on the line of the contrary poles or magnetic axis a¹, x¹, x², x².
16
"
«
Figure 4 represents a single induction wheel P mounted and placed opposite one
or several ordinary or superposed electro-magnets. The line x¹, x¹, is the magnetic
axis or direct line of the poles, the wheel being made entirely of iron. On the
same shaft (Figure 5) may be placed as required one or any indefinite number of
induction wheels having any desired number of coils, either in the circumferential
or longitudinal direction, one or several collectors being provided, according to the
effect desired. The boss on which all or some of the cores of the coils are fixed
may be solid or hollow and with or without iron discs or washers placed within.
The narrow wheels, grouped as in Figuro 5, prosent greater facilities in the
arrangement and working of the machine."
The connection of the cores of the coils directly to the same boss or base made
entirely of iron constituting a well-defined feature, as above explained, all arrange-
ments attaining the same result by changing the position of the cores relatively to
the shaft are intended to be included herein, if they have for result to place the
cores of the induction coils around the same boss made entirely of iron, thus forming
a single magnetizable mass. I will instance (although not the most suitable
arrangement) a disc of iron on which are fixed a number of iron cores covered with
wire, like electro-magnets. But the Invention does not include the same cores and
coils when placed upon a cylinder or disc made of an unimagnetizable material.
Such an arrangement is in fact found in certain magneto-electric machines, such as
the "Alliance and "Breguet" machines, which are therefore quite different in
principle to the present Invention. It has also been sought to diminish the rapidity
with which each coil is magnetized and demagnetized, in order to diminish tho
spark emitted at the collectors, which result is attained by extending the poles of
the electro-magnets so as to surround the induction wheel or wheels either partly or
wholly. Figures 4 and 5 show these extensions R, R', which only partially surround
the wheel in the Figures, but which it is easy to see might be sufficiently prolonged
to completely surround the induction wheels. The induction coils or helixes
furnishing the current to the rubbers a, a¹, at the moment of no current (magnetic
axis) in the coils or helixes which are changing polarity, the spark is consequently
considerably diminished and theoretically should cease entirely. I reserve the
employment of these curved polar extensions either to magnets or electro-magnets

page_text: in magneto or dynamo electric machines, whenever this extension covers several
independent coils, each having a special core. These extensions may be of different
forms; in certain cases they would be tubular or flat, according to the kind of
machine and position of the induction coils they surround. These polar extensions
applied to the inductor-magnets or electro-magnets never having been used in
magneto or dynamo electric machines having induction coils which are individually
separable, and each have a special core of iron, I reserve the right of so applying
them in all cases when they may be applicable. I of cousre except machines having
Siemen's armatures, such as the Wild and the Ladd machines, and machines such as
those of Worms de Romilly and of Gramme. In these machines these extensions
are indispensable and the principle is distinct from that which I describe, having in
one complete rotation but a single induction armature. The induction wheels of
this Invention may in any case be so disposed that I may apply either the system
with two independent circuits or that of sending the whole of the electricity
produced to the electro-magnets with a single circuit by employing one or several
collectors.
The copper covering the induction coils and electro-magnets of the different
machines may be modified according to the purpose in view, and may be in the
form of wire of various metals, covered or not, and fine or coarse, or it may be in
the form of metallic ribbons or strips placed edgewise or flat, the whole length of
the induction coils and the branches of the electro-magnets being covered if desired
with metallic ribbon. The wires may therefore be flat, round, or square, and of
different metals, covered or not.
The electro-magnets E, E¹, may be of any known form. Figures 4 and 5 show
them flat, but they may be round, tubular, concentric, or in bundles of iron wire.
They may be combined in all the ways above mentioned, that is to say, ordinary
or multiple, in single or superposed series. A superposed system comprises two
ordinary or multiple electro-magnets placed the one above the other, their poles
being in contact or separated by a metallic or other substance. The iron cores of
the coils of the induction wheels may be solid or hollow, divided or not, or com-
posed of bundles of iron wire.
In all cases the electro-magnets of the different kinds of dynamo-electric and
dynamo-chemical machines may be replaced by permanent steel magnets, the
machines thus becoming magneto-electric. An electro-magnet magnetized to
saturation is always more powerful than a permanent magnet of the same weight,
and it is therefore advantageous to use electro-magnets magnetized by the machine
itself, as they give better results with less weight.
All these machines yield continuous currents, that is to say, of the same direction,
but by employing the arrangement before described they will produce alternate
currents, which are preferable for the electric light. The polar extensions above
mentioned may be applied to other machines having multiple coils such as the
"Alliance" and "Brequet" machines. The discs or plates of these machines are of
brass or wood, or any other insulating material, and have induction coils either in
one or several series.
Figures 6 and 7 show how these machines, which are magneto-electric, that is to
say, have inductor magnets of steel, may be transformed into dynamo-electric
machines, that is to say, have electro-magnet inductors with the optional use of the
polar extensions R, R¹, of flat form, as above mentioned. The effect of using these
extensions being to diminish or avoid the emission of sparks at the collectors and
to augment the magnetizing surfaces; I employ the said extensions in all machines
having multiple coils individually independent of one another. These machines
thus modified might be capable, according as they are provided with one or several
collectors, of receiving the whole or part of the current with a single circuit in
accordance with the Patent No. 473, 1875. Although these machines differ entirely
in principle from the Lontin machines I reserve the right of applying to them these
modifications and improvements.
The induction wheel herein described may serve as an electric motor, whether it

page_text: be placed between the poles of permanent or electro-magnets suitably disposed. It
has a great motive power and may be actuated by a battery or by another dynamo-
electric machine. It may be specially constructed to act as an electric motor, but
any of the machines may be arranged to serve either as an electric motor or as a
dynamo-electric machine.
These dynamo-electric machines in which the whole of the current is returned or
thrown into the inducing electro-magnets, that is to say, having a single circuit
may be used as powerful brakes whilst retaining their suitability for the purpose
for which they were constructed, if desired. When the circuit is open they turn
without presenting any resistance, but as soon as the circuit is closed by the
slightest contact they oppose a considerable resistance to rotation. A machine
weighing 100 kilogrammes, for example, requires but the strength of a child to
work it when the circuit is open, but 6 to 8 horse power will be insufficient to
.overcome the resistance when the circuit is closed, and this without any complica-
tion of mechanical parts or the use of batteries. The machine itself immediately
generates the magnetism necessary to produce this powerful effect; I claim this
novel application as a brake in machines of any kind. This magnetic brake may
be constructed and applied in various ways.
All these details constitute important modifications and improvements applicable
to all kinds of magnoto-electric and dynamo-electric machines, and I therefore
reserve the absolute right to so apply and use them.
I also claim the following modifications in the employment of the induction
wheels to produce alternate currents. I use a small dynamo-electric machine, pro-
ducing invariable currents, to maintain the magnetization of the inductor electro-
magnets, but as shown in Figure 8 the electro-magnets A, A, are placed opposite
the extremities of a shaft furnished with two or more induction wheels without
coils which turn in front of their poles. These clectro-magnets and these wheels
are at a distance from each other, and on the part of the shaft between them I coil
the necessary quantity of wire to develop electricity therein. In this case, tho
wheels being unprovided with coils are of very simple construction, and the arrange-
ment of the wire is excessively easy and exempt from any liability to become
disarranged. It is of course necessary that the poles of the electro-magnets,
between which these wheels turn, should be similar for each of them, for it will be
readily understood that to produce the induction the magnetization of the shaft
must be in the direction of its length.
I may also invert the action of the apparatus by making the rotary shaft the
inducter, and having a series of induced parts B, B, Figure 9, arranged around in
a circle at which the currents may be taken without using any collector or friction
ring, as shown in Figure 10. In Figure 9 the central shaft is covered with wire,
the cross N, N, made of iron, serving as the polar extremity and as induction wheel.
I consider it advisable in this particular form to mount parallel on the shaft four
electro-magnets P, which add their action by alternation of polarity with the
central shaft, that is to say, that at the side where the north pole of the rotary
shaft is will be placed the south poles of these alternated and parallel electro-
magnets.
It is unnecessary to remark that the number of arms on the pinions and that of
the electro-magnets alternated therewith is optional Moreover, I find it convenient
to effect the magnetization of these machines by a special machine, producing
invariable currents similar to those described at the commencement of this Speci-
fication. I may also employ this modification of the wheel, as shown in Figure 11,
in which the wheel is exactly similar to that in Figure 8; but instead of making
it turn opposite two double poles only, I make it turn opposite a great number of
electro-magnet inductors placed outside the circumference. In this particular caso
the poles will be alternately dissimilar, so that one pole of one of these inductors
will be always between two poles dissimilar thereto. Thus, it will be readily seen
by the Drawing that in 1th of a revolution of the wheel its induction by magneti-
zation is reversed, and consequently in a complete revolution there are eight

page_text: reversals, and I thus obtain alternate currents. If on this wheel I place several
wires I can take several separate currents by means of a sufficient number of
friction rings placed on the shaft, and thus produce several electric lights with a
single coil of several wires. This machine, admitting of the use of cylindrical
electro-magnets its cost is greatly reduced.
Each cylindrical electro-magnet is provided at its extremity with a pole of iron
fixed on the cores of the electro-magnet in such manner as to leave a certain
amount of play, which admits of their being brought as close together as may be
desired to regulate the effect of the magnetization, and thus give the machine its
maximum effect without fear of the parts being deranged even by wear, although
in such event the parts may be easily readjusted to rectify any derangement caused
thereby.
I have stated above that I use a special machine producing currents uniform in
direction to effect the magnetization of these machines, but I would remark that I
may also magnetize them by any other source of electricity, producing invariable
currents, such as a battery, or a Lontin, Romilly, Gramme, Wild, Ladd, Siemen's,
Alliance, or Clarke machine, in which the currents are made uniform.
Although generally less preferable, I reserve the power to make uniform part of
the currents produced in these machines to furnish magnetism to the machine itself,
thereby, dispensing in this case with the use of a special machine for the purpose of
magnetization.
I will now describe further improvements in the construction of dynamo and
magneto electric machines. As above described, the dynamo-electric machines are
composed essentially of a large number of coils fixed on cores or arms of soft iron
around a boss which I have called an induction wheel, and which turns in front of
one or several electro-magnets. This induction wheel may be in one piece, but in
practice I prefer to fix each arm on a disc or cylinder, which may be of any metal,
but preferably of iron. Each carries a coil of copper wire, as described, but as
during the rotation these coils tend to fly off, I have avoided this by making the
cores of these coils b, b, of conical form with the base outwards, as shown, Figure 12.
Thus the coils cannot fly off, and, moreover, the induction is more easily effected,
the larger base being at the circumference, which admits of the speed of the
machine being reduced. To facilitate the passage of the wires which connect the
coils I provide a groove a between them on the discs, as shown, Figure 12.
To strengthen the induction wheels, whether they act as inductors or are induced,
I form the base of each arm of dovetail form, as in Figure 13.
When in certain cases the size of the electro-magnet conductors becomes con-
siderable, I construct them of several independent cores A, A, A, Figure 14, covered
with wire in the ordindary way, the similar poles being fixed to the same base S,
and having a single polar pièce P.
I have also made certain modifications in the rubbers which take the current.
When the rubbers are a little worn the point which takes the current becomes
modified in form so that the machine no longer yields its maximum effect. To
enable them to be replaced and adjusted more easily, I arrange them as follows,
and shown in Figure 15:-I fix on the frame of the machine a metal block B
insulated by wood or hardened india-rubber. To this block is hinged an arm D
bent into the form of the arc of a circle, so as to partly surround the collector at a
distance therefrom. On this arc is mounted a slide F carrying at its lower part the
rubbing point or blade. The slide F may be fixed in the proper position on the
arc by means of a set screw, and it may be adjusted during the working of the
machine. A spring R maintains the necessary contact of the rubbers with the
collector.
I will now describe a new rubber for larger machines, which avoids the wear
above referred to, and reduces the resistance due to friction. It consists of a
toothed wheel, each tooth of which is so mounted as to be perfectly insulated; each
of these teeth represents a plate of the old form of collector, and consequently a
point at which the current is taken. A second wheel, entirely metallic, gears with

page_text: the collecting wheel. It is movable with its axis in a quadrant shaped support,
which admits of the whole being placed in the best position relative to the first
wheel to obtain the maximum effect of the machine.
Figures 16, 17, 18, 19 represent this arrangement, Figure 16 showing a face view,
Figure 17 a plan, Figure 18 a transverse section of the collecting wheel, and Figure
19 a section on line 1, 2; Figure 18 a, a, are two metal plates forming the body of the
collecting wheel A, and having each an internal circalar groove b, in which are
successively inserted the metal teeth c, which are notched laterally at d, Figure 20,
to receive the wooden keys e, Figure 21, so shaped as to fix and lock the teeth
in place, at same time completely insulate them, the teeth and keys being in-
troduced at an opening made for the purpose in the plates a, a. The last key
introduced locks the whole, and is itself fastened with a bolt. f represents the con-
nection of the wires b with the teeth. g, g, are brass quadrants concentric with
wheel A, insulated from the bars h, h¹. On these quadrants are fitted the adjust-
able slides i, 1, which carry the upper and lower metal wheels j, j³, and by shifting
which these wheels may be placed in the proper position.
Having described the nature of the said Invention, and the manner of perform-
ing the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,-
First. The rotary induction wheel or induced wheel described and illustrated in
Figure 4, consisting essentially of a cylinder, disc, tube, or ring of metal, preferably
of iron, on which are mounted soft iron cores covered with copper in the ordinary
way, so that an clectric current is produced by magnetic induction on the passage
of the cores in front of the poles of permanent magnets or electro-magnets, as
described.
Second. The transformation of such induction wheel or induced wheel into an
inductor wheel by the action on it of any source of electricity as set forth, so that
it may be used to produce induction currents in fixed iron cores (covered with
copper in the ordinary way) disposed around said wheel, and thus enable currents
to be taken separately from each of theso cores.
Third. Arranging upon the same axis several induction or induced wheels, each
provided with collectors, commutators, or friction rings, as specified, in order to
obtain as many distinct currents as desired.
Fourth. In machines producing continuous currents, I claim returning the whole
of the electricity into the inductor electro-magnets, as specified, and thereby to
considerably increase, in certain cases, the effect obtained.
Fifth. The application of these improved dynaino and magnoto electric machines
as motors when supplied with an electric current.
Sixth. Placing the copper coils to be induced either between the induction
wheels, as specified, instead of on the arms of said wheels, also placing them both
upon said arms, and in the intervals between each wheel.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Seventeenth day of February, in the year of our
Lord One thousand eight hundred and seventy-seven.