IMPROVEMENTS IN ARMATURES FOR ELECTRIC GENERATORS AND MOTORS
Year: 1885

page_text: I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of my invention for "IMPROVEMENTS IN ARMATURES FOR ELECTRIC GENERATORS
AND MOTORS" to be as follows:-
This invention relates to armatures for dynamo-electric machines and motors,
and is more especially designed to provide a simple and effective means for
preventing the formation and circulation of neutralizing currents, or the so called
Foucault currents," in the frame or body of the armature; to aid in keeping the
armature cool when under the influence of induced currents'; and to prevent any
humming noise in a machine when it is in operation.
"
To this end my invention consists in the novel construction hereinafter
described.
According to the said invention the foundation of the armature consists of a thin
flat disc, wheel or plate of cast or soft iron or other magnetic material having upon
its inner periphery or edge, projections which serve for holding the said core to the
hub of the shaft and to form slots to receive the coils of copper wire; and which
also serve as lateral abutments or supports upon which' are wound or placed coils
of unsinulated soft iron wire to form with the said disc the core of the armature in
the manner more fully described hereinafter.
'
The size of the iron wire for the said coils is determined by the width of the
abutments or shoulders, and the size of the armature desired. Whatever size of
wire and number of layers there may be, it is desirable to have the wire flush with
the outer faces of the projections and shoulders and extending upwards on the
sides of the disc to the top or outer edge thereof. The calculation for this is easy;
for instance if the lateral projection of the shoulder or abutment is, say, one half
Prica 8dl

page_text: inch wide, then five wires of a diameter of one tenth inch each will form a surface
at the sides flush with the ends of the said abutments, and if the disc is say two
inches high or broad then it would require twenty layers of the same wire to form
a surface flush with the top or exterior periphery of the disc. In this case two
thin flat discs of uninsulated wire a half inch thick by two inches broad are
formed.
•
These iron wire coils may be wound directly upon the disc, or they may be
wound upon a cast iron or other former, and afterwards placed in position upon
the disc; the latter is the mode I prefer, and I also prefer to have each lateral
wire or layer in one piece, although the whole coil may be made of one continuous
wire. When the coil of iron wire is formed or wound the ends of the wire may be
secured by soldering or brazing, or by screws, rivets or bolts.
The mass of wire may be also held firmly together as a coil by soldering or
brazing in places. These coils thus become almost like solid rings or wheels and
can be handled with ease and facility, to free the iron wire as well as the disc from
the effects of the acid or flux used in soldering or brazing; the coils may be boiled
(and if need be the disc and coils together) in oil or other substance to prevent
rusting.
I sometimes arrange two or more rings or discs together end wise to give length
to the cylinder, or a long cylinder may be formed without the projecting discs and
the iron wire wound directly upon it, or formed into. coils and placed upon the
cylinder. I prefer, however, the arrangement with the discs, because, for one
reason, the edges of the said discs furnish a solid iron base or foundation for screws
or bolts to hold in place pieces of wood or other material which separate the
transverse coils of copper wire. In this respect the peripheral edges of the discs
are of considerable importance as they furnish a means of securely building up, and
fastening, the parts of the armature in a symmetrical and substantial manner
which could not be done if screws or bolts had to be placed in the iron wires
forming the iron coils.
Around the said core are wound copper wire coils, the said coils being wound
between the projecting points or abutments on the disc.
The said coils are separated from each other by V-shaped plates or pieces of
material. Other pieces separate the coils at the outer periphery of the armature
and connect with the ends of the first mentioned piece.
For armatures in dynamo-machines, or machines for generating a current of
electricity, I prefer to make these plates or pieces, of wood, although they may be
made of any suitable non-magnetic material.
For armatures for motors, these pieces may be replaced by soft or cast iron, that
is the space which is filled up with wood or other non-magnetic material for
generators is filled up with iron or other magnetic material in an armature
designed for a motor. The said plates or pieces are formed of such size and shape
as to be flush with the exterior or outside surfaces of the copper wire coils of the
armature. They are held in place by rivets or screws. These plates or pieces are
provided with grooves or slots which are directly in connection with openings on
the outside surface of the iron wire or iron core of the armature. The object of
these grooves, cavities, and openings is to relieve the iron from the contact of the
wood as much as possible, to prevent the heating of the iron, and to furnish an
outlet for the heat when generated. These grooves or cavities may be entirely
dispensed with if desired.
The main object of the wooden or other plates is to form continuous and flush
surfaces with, and between, the coils of copper wire to prevent the noise or hum of
an armature while in motion, besides forming flanges or abutments to secure the
sides and ends of the wire coils. The points or projections within the disc serve
for the purpose of securing the armature to the hub and shaft. Holes or openings
are formed through the web of the hub for ventilation, and to reduce the weight.
A deep slot or groove is formed around the periphery of the hub and extends

page_text: through the rim and into openings or holes so that the air can circulate freely.
At each angle or point of meeting of a series of faces formed upon the periphery of
the hub is cut a V-shaped groove which extends across the face or edge of the hub.
The points or projections with the disc fit into these V-shaped grooves and serve to
rotate the armature with the hub.
An armature formed in accordance with the foregoing description presents a
smooth even peripheral surface, and by substituting wood for metal between the
coils the weight is greatly reduced, the magnetic pull upon the jaws of the field
magnets is reduced, and by the smoothness and evenness of the exterior surface all
noise and humming is prevented; the grooving in the wooden plates ventilates the
coils of iron wire of the core and the particular formation of the disc and the iron
wire coils combined as described prevents the circulation of so-called "Foucault
currents" and consequently the heating of the armature is prevented.
T
01
3
2
1007
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: COMPLETE DI ECIFICATION.
4
I
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F
Improvements in Armatures for Electric Generators
and Motors.
'I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention relates to armatures for dynamo-electric machines and electric
motors.
The said invention is chiefly designed to provide, in a simple and effective
manner, for preventing the formation and circulation of neutralizing currents, or
the so-called "Foucault currents," in the frame or body of the armature; for
keeping the armature cool; and for preventing or avoiding humming in the
machine when in operation.
In the accompanying drawing,
Figure 1 is a side elevation, partly in vertical section, of an armature of the ring
type, constructed in accordance with the present invention, some of the parts being
removed.
Figure 2 is a side elevation, and
Figure 3 an edge view, of the hub or central portion of the said armature.
Figure 4 is a side elevation, drawn to a reduced scale, shewing part of another
armature constructed according to the present invention.
Figure 5 is an edge view, partly in vertical section, of the armature shewn in
Figure 1, some of the parts being removed.
Figure 6 is a section on the line x, x, Figure 1, some of the parts being removed..
Figure 7 is a side elevation, and
Figure 8 an edge view of the core or frame of the armature.
Figure 9 is a section on the line x1, x¹, Figure 7.
Figures 10 to 13 are different views hereinafter referred to shewing details of
construction.
Figure 14 is a plan, and
Figure 15 a side elevation of an armature of the drum or cylinder type,
constructed according to the present invention.
Figure 16 is a plan, drawn to an enlarged scale, of part of the said armature.
Like letters indicate corresponding parts throughout the drawing.
"
A is a flat ring or annular plate of cast or soft iron or other magnetic material.
This plate constitutes the foundation on which the other parts of the armature are
built; I, therefore, term the said ring or plate the "spine or "backbone" of the
armature. The said ring or spine has upon its inner edge wedged-shaped pieces or
teeth a, which project laterally from each side of the said ring or spine, as shewn
in Figure 9, and between which the armature-coils B are wound. These teeth or
projections constitute lateral abutments or supports upon which are wound or placed
coils 6 of uninsulated soft iron wire, one on each side of the ring or spine A. These
coils form, with the said ring or spine, the core or frame of the armature,

page_text: The size of the iron wire for the coils b is determined by the width of the
abutments or supports a and the desired. dimensions of the armature. Whatever
may be the size of the wire used and the number of layers thereof wound upon
the ring or spine A, it is desirable that the outer sides of the coils b should be flush
with the outer edges or faces of the projections a, and that the external diameter of
the said coils should be such that they will be flush with the periphery of the ring
or spine A. The calculation for ascertaining the size of wire required is easily
made; for instance, if the projections or abutments a extend laterally from the
ring or spine A say one-half of an inch, then five turns of wire, of a diameter of
one-tenth of an inch, will extend to the edges of the projections a and form a
surface at the outer sides of the coil flush with the outer edges or faces of the said
projections, and, if the ring or spine A is say two inches from its inner edge to its
periphery, twenty layers of the said wire will be required to ensure that the
periphery of the coil shall be flush with that of the said ring or spine. In this
case, there will be two thin flat discs or coils of uninsulated wire, each one-half of
an inch wide by two inches thick.
:
These iron wire coils are either wound directly upon the ring or spine A, or they
are wound upon a cast iron or other former, and afterwards placed in position upon
the said ring or spine; the latter mode is preferable. Moreover I prefer to have
each layer of wire in one piece; but, if desired, the whole coil may be made of one
continuous length or piece of wire. When the coil is formed or wound, the ends of
the wire may be secured by soldering or brazing, or by screws, rivets or bolts. The
convolutions of wire forming each coil may, if desired, be held firmly together by
soldering or brazing in various places. The said coils are thus made like solid
rings or wheels and can be handled with facility. To protect the iron wire and the
ring or spine A against injurious effects resulting from the action thereon of the acid
or flux used in the soldering or brazing, the coils b and the said ring or spine are
sometimes boiled in oil or other substance which will prevent rust.
Referring to Figure 1, there are four.copper wire coils B shewn in elevation,
three in the upper half and one in the lower half of the armature, while, on the
right and left hand sides of the armature are two coils shewn in section on the
line x, x, Figures 5 and 6, the remaining two coils being removed..
C, C are V-shaped blocks or pieces of wood or other non-magnetic material which
separate the coils B on each side of the core or frame of the armature. c, c are
blocks or pieces of similar material which separate the coils. B at the periphery of
the armature. These blocks or pieces c are connected with the ends of the blocks
or pieces C, as shewn in Figures 5, 6, and 14. For the armatures of dynamo-electric
machines, that is to say, machines for generating electricity, I prefer that the blocks
or pieces C, c should be of wood, although they may be made of any other suitable
non-magnetic material. But, for the armatures of electric motors, the said blocks
or pieces are made of soft or cast iron, that is to say, the spaces which would be
filled with non-magnetic material in an armature for a machine for generating
electricity are filled with iron or other magnetic material in an armature designed
for a motor. The said blocks or pieces are made of such size and shape that, when
in place, they will be flush with the exterior surfaces of the armature coils B.
They are held in place by rivets or screws d. The said blocks or pieces are,
moreover, formed with grooves or channels e, as shewn in Figures 5, 6 and 14 and
more in detail in Figures 10, 11, 12 and 13. These grooves or c channels are formed
in that side of each of the said blocks or pieces next the iron core or frame of the
armature; and apertures or cavities f are provided, as shewn in Figures 5 and 14.
The object of these grooves and apertures or cavities is to avoid, as. far. as
practicable, the contact of the iron with the wood, to prevent the heating of the
iron, and to furnish an outlet for the heat when generated. These grooves or
cavities are, however, entirely dispensed with, if desired.
J
The main objects of the blocks or pieces C, care to form continuous and flush
surfaces with, and between, the coils of copper wire, to prevent noise or humming
when the armature is in motion, and to form flanges or abutments for securing or

page_text: supporting the sides. and ends of the wire coils. When the said blocks or pieces
are properly arranged and secured in place, they complete the contour or finish of
the armature. Two of the screws d, which secure each block C in place, enter the
adjacent wood block or piece c; the remaining screw d enters the iron projection
or abutment a, as shewn in Figure 6.
The grooves e shewn in section at the sides of the coils b at the upper part of
Figure 6 appear elongated by reason of the diagonal direction of the sectional cut.
D is the hub or central part of the armature, which has holes or openings g
formed through the web thereof for ventilation and to reduce the weight of the
armature. A deep annular groove or channel h is formed in the hub D and extends
through the same to the openings or boles g, so that air can circulate freely through
the said hub. At each angle or meeting point of the octagonal faces of the
periphery of the hub D is cut a V-shaped groove or notch i which extends across
the said hub. When the ring or outer portion of the armature is placed upon the
hub, the wedge-shaped teeth or projections a fit accurately within these V-shaped
grooves or notches, and thus ensure the rotation of the said ring or outer portion of
the armature with the hub.
In the modification of my invention shown in Figures 14 to 16, two rings or
spines A, together with their coils 6 of iron wire, are placed side by side to form a
drum or cylinder, the dotted line ³, ³, Figure 16, showing the plane of contact of
the said rings or spines. As many of these rings or spines and coils are used as are
required to form a drum or cylinder of the desired length. I sometimes form a
long cylinder without projecting rings or spines and wind the iron wire directly
upon the said cylinder, or I form the said wire into coils and place the said coils
upon the said cylinder. I prefer, however, the arrangement with the rings or
spines, because, for one reason, the edges of the said rings or spines furnish a solid
iron base or foundation to receive the screws or bolts that hold in place the blocks
or pieces of wood or other material, which screws or bolts enter holes k in the rings
or spines A or holes in the teeth or. projections a. In this respect, the said
rings or spines are of considerable importance, as they afford the means for
permitting the building up and fastening of the parts of the armature in a
symmetrical and substantial manner which would be impracticable if the screws
or bolts had to be secured in the iron wires forming the coils b.
Figure 16 represents the spinal core or frame of a drum armature before it is
placed upon the hub or shaft and before it is provided with the wooden blocks or
pieces and the coils of copper wire. Figures 14 and 15 shew the said core or frame
with the wooden blocks or pieces fitted in place and the copper wire coils wound
upon it.
Figure 4 shows, in side elevation, an armature built up in the manner last above
described, the coils being wound as in a ring armature.
An armature formed in accordance with the foregoing description presents a
smooth or even peripheral surface, and, therefore, does not produce humming
when rotated. By substituting wood for metal between the armature coils, the
weight of the armature is greatly reduced and the magnetic pull upon the jaws of
the field-magnets is diminished; moreover the grooves or channels in the said
blocks or pieces ensure the ventilation of the coils of iron wire, and the peculiar
formation of the ring or spine and its iron wire coils as above described prevents
the circulation of so-called "Foucault currents," thereby avoiding heating of the
armature.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I wish it understood that I claim :-
First: The employment, in an armature, of a flat ring or annular piece of
magnetic material with a coil of iron wire on each side thereof, substantially as,
and for the purposes, set forth.

page_text: Second-The provision of the internal projections or teeth on the said ring or
annular piece fitting into grooves or notches in the hub or central portion of the
armature, substantially as, and for the purpose, set forth.
Third-The employment of the blocks or pieces of wood or other non-magnetic
material (with or without the grooves and apertures) between the armature coils,
all substantially as, and for the purposes, set forth.
Fourth-The improved armature consisting of the parts constructed and
combined substantially as described with reference to either of the forms or
modifications shown in the drawing, for the purposes specified.
D
1
1000
HASELTINE, LAKE & Co.,
Agents for the Applicant.