IMPROVEMENTS IN DYNAMO OR MAGNETO ELECTRIC MACHINES
Year: 1882

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine, Lake,
دو
& Co Patent Agents, Southampton Buildings, London for an invention of
"IMPROVEMENTS IN DYNAMO OR MAGNETO ELECTRIC MACHINES Commu-
nicated to him from abroad by Edward Weston of Newark, New Jersey,
United States of America
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 8th June 1882.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co, Patent Agents,
Southampton Buildings, London " IMPROVEMENTS IN DYNAMO OR MAGNETO
ELECTRIC MACHINES [A communication to him from abroad by Edward Weston
of Newark, New Jersey, United States of America]
This Invention embraces improvements in winding, and connecting to the
commutator, the armature-coils of dynamo electric machines, which employ as the
armature, a cylindrical core mounted in such manner as to be capable of revolution
between the polar faces of a system of magnets.
The said Invention comprises a system or method of winding the armatures of
machines which are more especially designed for furnishing currents of high electro
motive force; and a system or method of winding the same or similar armatures
for the production of currents of low electro-motive force, but great quantity.
Machines have heretofore been constructed in which the armatures were
successively normal with two systems of coils, one overlying the other, each system
being wound in diametrically separate divisions, and each division or coil being
connected to the next adjoining division by a loop from which connection was
made to one of the commutator segments.
In another type of machine, an improvement on this method of winding was
embodied, which differed from the original only in the fact that each system of
coils was wound upon itself so that the two systems should lie alongside each other
in the divisions of the armature, and equidistant from the centre of the same. By
this means the two coils of each armature division are practically of the same

page_text: length and consequently opposed severally the same degree of resistance to the
passage of the induced currents.
The first part of my present invention is designed to render still more perfect
.the above described systems of winding, as by the methods of construction which
it involves, both time and labor are saved, and a more serviceable armature
produced.
The present Invention consists mainly in alternately superposing the several
divisions of the two systems of coils, so that the distinguishing characteristics of
both the above described methods are in a measure combined.
According to this invention the armature is by preference composed of a number
of plates or discs of magnetic metal, strung on a shaft and held at short distances
apart by collars of insulating material of considerably less diameter than the discs.
When thus built up the cylinder is provided with longitudinal grooves or recesses
in which the coils are to be wound.
In any two diametrically opposite recesses of the armature, an insulated wire of
the desired size is wound, until one fourth of the said recesses is filled with a coil.
The two ends, are brought out and temporarily secured. The armature is then
turned half way round and a coil is wound upon the first. When the same number
of layers is reached; a loop is formed in the usual manner and the winding is
continued alongside of the first coil, until another coil is formed. The wire is then
cut off, forming a free end, which is temporarily secured. The armature is again
turned half back and other coils wound in a precisely similar manner, and this
plan is followed until all the recesses are filled, each with four divisions or sections
of the two systems of coils, said sections being alternately superposed in regular
order around the armature. The free ends left, after completing the winding, are
joined so as to form a practically continuous conductor, and from the loops formed
in this manner, and those originally existing, connection is made to the commutator
segments.
By this arrangement the two systems of coils are very nearly of equal length
and equal resistance, and their mean distances from the centre of revolution are
the same.
I prefer usually to wind the two systems, so that each recess will contain four
divisions of coil. I may however, vary this number; for instance, each recess may
contain only two, or more than four. I would also state that I do not confine
myself to the method herein proposed for winding the coils, as other plans may be
followed for reaching the same relative distribution of the several divisions.
The size and character of the conductors employed, and the uses for which the
machine is intended, will determine the number of layers in each coil, or section of
coil, but in general practice, I prefer to use this method of winding on machines
intended for running arc lights, or for other purposes when a current of high
electro-motive force is necessary.
When currents of great quantity are to be generated I pursue the plan of
winding which constitutes the second part of my invention, and which I will now
describe.
If, upon the surface of a cylindrical armature, or in the grooves cut thereon a
continuous conductor be wound, one turn in each groove, and a loop be formed at
the points where the conductor passes from one groove to the next as above
explained, one half as many loops will be formed, as there are sections of wire
around the armature.
If then the same conductor be again wound about the cylinder in the same
manner as before, or if another conductor be wound either simultaneously with the
first, or afterwards there are, or may be, formed a complete circle of loops around
the armature, there being as many loops as there are sections or divisions of the
armature-coils. Let these loops be then connected, in order, to the segments of a
commutator, and the whole properly mounted in a magnetic field, then all the
segments on opposite sides of a line bisecting the commutator through the neutral
points will be of opposite polarity, so that if collecting brushes be applied to the

page_text: segments, at or near, the points of maximum intensity, the result is a machine, the
electro-motive force of which is the aggregate electro-motive force of all the sections
of coil on the armature.
In order therefore to render these machines capable of producing currents of
minimum intensity and great quantity, and at the same time secure the other
advantages accruing from the described method of construction, I take off loops
from the several sections of conductor at two points instead of one, employing for
this purpose two commutators, and two sets of collecting brushes.
The loops must be taken off from the sections at such points as will ensure an
equal division of the current between them. For which purpose I form, each coil
or section of the armature conductor with an odd number of turns and take off the
loops or connections at diagonally opposite points, with respect to the armature
upon which they are wound.
The coil, as stated above, is wound continuously about the armature and upon
itself until a complete circle of loops is formed.
Two loops may be taken off at the junctions between the several coils, and also
from the middle of each coil. Loops thus formed are in the same coil always of
opposite polarity.
When heavy wires are used, they may be cut wherever it is desired to form a
loop, to avoid bending, and instead of winding the coils back on themselves, as is
done in other forms, each one may be formed successively and separately alongside
of each other.
The core may be composed of perforated plates fixed on a shaft and separated
from each other by the thin discs of insulating material. Upon the cylindrical
surface of this core, or in grooves cut for their reception, the coils are wound, the
connections from each being made as above described by means of the loops or
united ends, to arms forming parts of the commutator-segments.
From this machine two separate currents may be taken and applied to different
purposes, or the two sets of brushes may be connected to give a single current, the
brushes being joined either in multiple arc or in series.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
8th December 1882.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake and Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN DYNAMO OR MAGNETO
ELECTRIC MACHINES A communication to me from abroad by Edward Weston,
of Newark, New Jersey, United States of America.
"
This invention relates chiefly to improvements in winding, and connecting to the
commutator, the armature coils of dynamo-electric machines wherein the armature
is a cylindrical core mounted in such manner as to be capable of rotation between
the polar faces of a system of magnets.
The said invention comprises a system of winding the armatures of machines
which are more especially designed for furnishing currents of high electro-motive
force; and also a system of winding similar armatures for the production of
currents of low electro-motive force but great quantity.
Machines have heretofore been constructed by the said Edward Weston, in which
the armatures are successively normal with two systems of coils, one overlying the
other, each system being wound in diametrically separate divisions and each
division or coil being connected to the adjoining division by a loop from which
connection is made to one of the commutator-segments.
In another type of machine an improvement on this method of winding has been
embodied, which differs therefrom only in the fact that each system of coils is
wound upon itself, so that the two systems lie alongside of each other in the
divisions of the armature and equidistant from the centre of the same. By this
arrangement the two coils of each armature division are practically of the same
length and consequently offer severally the same degree of resistance to the passage
of the induced currents.
The first part of the present invention is designed to render still more perfect the
above described systems of winding, and, by the methods of construction comprised
in this part of the said invention, to save time and labor and to produce a more
serviceable or efficient armature than could be obtained by the methods heretofore
⚫employed.
The first part of this invention consists mainly in alternately superposing the
several divisions of the two systems of coils, so that the distinguishing characteristics
of both of the above described methods are, in a measure, combined.
In the accompanying drawing
Figures 1 and 2 illustrate a practical embodiment of this part of the present
invention
Figure 1 is a perspective view of part of an armature with the commutator and
connections.
Figure 2 is a section (drawn to an enlarged scale) at right angles to the axis of
the armature-cylinder, illustrating the disposition of the coils.
The remaining figures of the drawing are hereinafter described.
The armature is, by preference, composed of a number of plates or discs of
magnetic metal mounted on a shaft and held at short distances apart by collars or
rings of insulating material of considerably less diameter than the said discs. When
thus built up the cylinder is provided with longitudinal grooves or recesses in
which the coils are wound.
In any two diametrically opposite recesses of the armature, as A, A1, an insulated
wire of the desired size is wound until one fourth of the said recesses is filled with
a coil a.
The two ends of this coil are brought out and temporarily secured. The
armature is then turned half round and the coil b is wound upon the coil a. When

page_text: the same number of layers is reached, a loop 62 is formed in the usual manner and
the winding is continued alongside of the coil a until the coil è is formed. The
wire is then cut off forming a free end which is temporarily secured. The armature
is again turned back and the coils d, e are wound in a precisely similar manner;
and these operations are repeated until all the recesses are filled, each with four
divisions or sections of the two systems of coils, the said sections being alternately
superposed in regular order around the armature. The free ends, left after
completing the winding, are joined so as to form a practically continuous conductor,
and, from the loops formed in this manner, and those originally existing, connection
is made to the commutator-segments
By this arrangement the two systems of coils are very nearly of equal length
and equal resistance, and their mean distances from the centre of rotation are the
same.
•
I prefer, usually, to wind the two systems which are represented respectively by
the dark and light lines, so that each recess will contain four divisions of the coil;
may, however, vary this number; for instance, each recess may contain only two,
or more than four, coils. Moreover, I do not confine myself to the process herein
proposed for winding the coils, as others may be adopted for attaining the same
relative distribution of the several divisions.
The size and character of the conductors employed, and the particular purposes
for which the machine is intended, will determine the number of layers in each
coil, or section of coil, but in general practice I prefer to employ the method of
winding above described in machines intended for supplying are lights, or for other
purposes, where a current of high electromotive force is necessary. When currents
of great quantity are to be generated, I adopt the method of winding illustrated in
Figures 3, 4 and 5, which constitutes the second part of the present invention.
Figure 3 is a central longitudinal section of a complete armature with its appur-
tenances, the coils of which armature are wound and connected to the commutator
in accordance with the second part of the present invention.
Figure 4, is a diagram illustrating a method of winding heretofore employed.
Figure 5, is a similar diagram illustrative of the improvements hereinafter set
forth.
If, upon the surface of a cylindrical armature, or in grooves cut therein, a con-
tinuous conductor be wound, one turn in each groove, and a loop be formed at the
points where the conductor passes from one groove to the next groove as above
explained, one half as many loops will be formed as there are sections of wire
around the armature.
If then the same conductor be again wound about the cylinder in the same
manner as before, or if another conductor be wound either simultaneously with
the first, or afterwards, there will be formed a complete circle of loops around
the armature, there being as many loops as there are sections or divisions of the .
armature coils. Let these loops be then connected, in order, to the segments of a
commutator, and the whole properly mounted in a magnetic field, then all the
segments on opposite sides of a line bisecting the commutator through the neutral
points, will be of opposite polarity, so that if collecting brushes be applied to the
segments, at, or near, the points of maximum intensity, the result will be a machine,
the electromotive force of which is the aggregate electromotive force of all the
sections of coil on the armature.
In order therefore to render these machines capable of producing currents of
minimum intensity and great quantity, and, at the same time, secure the other
advantages accruing from the above described method of construction, I take off
loops from the several sections of the conductor at two points instead of at one
point, and I employ for this purpose two commutators, and two sets of collecting
brushes.
The loops must be taken off from the sections at such points as will ensure an
equal division of the current between them. For this purpose I form each coil or
section of the armature conductor with an odd number of turns and take off the

page_text: loops or connections at points diagonally opposite with respect to the armature
upon which they are wound.
This mode of construction will be understood by reference to Figures 4 and 5.
In Figure 4, a section of continuously wound wire is shown, the loops being taken
only at the junction of each coil with the next coil as represented at m, m.
This wire is wound continuously about the armature and upon itself, until a
complete circle of loops is formed.
In Figure 5 the same system of winding is adopted but two loops are taken off,
at the junctions between the several coils, and also from the middle of each coil.
as shewn at n, o. Loops thus formed are, in the same coil, always of opposite
polarity.
When heavy wires are used, they may be cut wherever it is desired to form a
loop to avoid bending, and instead of winding the coils back on themselves, as in
other arrangements, they may be formed successively and separately alongside
each other.
In Figure 3 the core is shown as composed of the perforated plates B fixed on a
shaft C and separated from each other by the thin discs D of insulating material.
Upon the cylindrical surface of this core or in grooves cut for their reception
therein, the coils E E are wound, the connections from each coil being made, as
above described, by means of the loops or united ends F, to the arms G forming
parts of the commutator-segments.
From this machine two separate currents may be taken and applied to different
purposes, or the two sets of brushes may be connected to give a single current, the
brushes being joined either in multiple arc or in series.
Having thus fully described the said Invention as communicated to me by my
Foreign correspondent and the manner of performing the same, I wish it understood
that I Claim, in, or for, a dynamo or magneto electric machine :-
First. An armature wound with two systems of coils in diametrically separate
divisions, the divisions of one system being alternately under and over those of the
other system, and the said divisions being looped together and connected to the
commutator, substantially as described, and for the purpose specified.
Second, An armature having recesses or grooves, wound with two systems of
coils in diametrically separate divisions, each recess containing four of such divisions,
the divisions of one system being alternately under and over those of the other
system, and all being looped together and connected to the commutator segments,
substantially as shown and described, and for the purpose specified
Third, A cylindrical armature wound with a double system of continuous coils
in separate divisions, in combination with two independent commutators connected
respectively with loops taken from diagonally opposite portions of the said divisions,
substantially as described, and for the purpose specified.
Fourth, An armature wound with a double system of continuous coils in
separate divisions, in combination with two independent commutators connected
respectively with loops taken from the junctions of the several divisions of coils,
and from the middle of each of the said divisions, substantially as set forth, and for
the purpose specified.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Eighth day of December in the year of Our Lord One
thousand eight hundred and eighty two.