IMPROVEMENTS IN MAGNETIC ELECTRIC MACHINES
Year: 1884

page_text: HENRY FRANCIS JOEL, of 44 Lavender Grove, Dalston, London, in the County
of Middlesex, Electrical Engineer, do hereby declare the nature of my invention
for "
IMPROVEMENTS IN MAGNETIC ELECTRIC MACHINES," to be as follows:-
:-
My Invention relates to an improved construction of Magnetic Electric Machines.
I construct a Dynamo Electric Machine with two upright field magnets, bridged, or
joined across by two pole pieces, the armature revolving between them, and the
whole being suitably mounted with bearings, and base plates. I make the cores
of the field magnets of a laminated construction with iron plates, bars, or tubes, to
prevent or neutralize as much as possible the formation of so called "Foucault" or
eddy currents. I fit the plates, or bars into solid iron pole pieces, and cut, mill, or
cast slots, or grooves for the purpose in the ends of these pole pieces, into which
the ends of each plate or bar, or a number of core plates or bars, side by side, are
fitted, the whole being secured by bolts; this construction makes a good magnetic
connection between the core bars, and the pole pieces. I make corrugated holes,
or grooves in the body of the pole pieces, for the purpose of concentrating the
magnetic lines of force at any desired part of the poles, and also to prevent the
formation of eddy currents. I may reverse the foregoing construction by making
the pole pieces of laminated iron plates, and the magnet cores of solid iron, fitting
them together in the same way as described; or I may make the whole of the iron
magnet cores, and pole pieces, of laminated iron plates, bars, or strips, or tubes, so
that the cores, and pole pieces of the Dynamo are built up of thin strips, or bars
of iron, in one whole piece or frame, or made of separate parts joined together, and
I may insulate these thin core plates and poles, the one set from the other, in layers,
so that the completed core and poles is built up of a number of distinct and
separate magnet core frames side by side, in order, still further to decrease the loss
due to eddy currents. I connect, and join the laminated cores and poles the one to
the other, and keep them in their correct shape, and place, by means of square
bolts; or by stepping the ends of the one set of bars for the other set to be fixed
to; or by fixing caps, or shoes with milled slots, over the joints; and also by
set pins.
I provide and fix one or more polar extension pieces, or plates, which I fit
between, over, or through the plates or solid pieces at the poles, these may be made
in one piece, with milled or cast grooves, or slots, or of thin plates; and of "any

page_text: desired shape, and these polar extension plates, or pieces, can be utilized to fix and
secure the junctions to prevent them from shifting. By the foregoing described
special construction of Dynamo machine frames I obtain several distinct advantages
over the usual solid construction, as follows :—
I obtain the same, or a greater degree of magnetism with my laminated cores,
than solid cores would give.
I concentrate the magnetism at the poles.
I obviate to a great extent the loss due to "Foucault" currents.
The advantages in the mechanical constructions are :—
Decreased weight for the same result. The cores can be made of the best iron.
Each strip or shaped part can be cut or stamped by machinery. Machines with
narrow, or broad frames, can be readily made by decreasing, or increasing the
number of the same sized plates, side by side. The spaces between the bars allows
free ventilation.
Each part is detachably attached. I may use the jointing caps, or shoes, as the
pole pieces, and make two or any number of poles in that way.
I may use the
above laminated construction for any shaped Dynamo, for instance of rectangular
shape, such as described, or a circular, or other curved shape, if I make a circular
shaped core, I divide the circle in two halves, with two poles, and only two joints,
to make; or I may divide the circle into a number of segments, with the junction
pieces to form the poles, the joints being made by milled slots as before described.
I may make two or any number of field magnets, side by side, with pole pieces
bridging across and connecting them.
I construct the cores of my armature in a manner similar to the cores of the field
magnets i,e, with laminated iron plates. A circular, disc or drum shaped armature,
is built up of a number of divided, and seperate segmental shaped plates, formed
into sections, and joined together by overlapping, and interlocking the ends of the
sections. This ring core is secured to spokes of a central wheel, or to two end
wheels, of non magnetic material, by bolts fixed parallel to the axis of rotation;
the same bolts holding the sections of the core together. The segmental plates
forming the armature, may be stamped with projecting teeth or radial prolongations
at intervals in order to bring the body of the iron core as close as possible to the
field magnets. I insulate these plates, and bolts, and spoked wheels and all of
them, the one from the other in order to avoid all loss from "Foucault" or eddy
currents. The same advantages I have enumerated for my field magnet cores
apply equally to my armature
I arrange, and fit the insulated wire coils, for both the field magnet cores, and
the armature cores, in a special and novel manner. I wind the wire coils before-
hand, on seperate bobbins, in a lathe or otherwise, and then thread or pass them
over the cores. I may build up each field magnet of a number of such coils, made
of thin, thick square, or other shaped section and use thick wire coils, or coils
made of thin wire, or a combination to make electro magnets for a series, shunt, or
compound wound Dynamo machine, of any required resistance I also make the
coils to fit the one concentrally over the other. It is obvious that with suitable
coils any desired combination can be made. I may interspace the coils on the field
magnet cores with iron extension polar pieces, and I may interspace the coils on the
armature, with radial projecting and dividing pieces, these latter I make to fit over,
and between the plates of the armature and under the coils, and be kept in place
by the coils, each succeeding coil as it is threaded on the sections of the armature
core, and placed in position, keeps the preceding seperating extension piece in its
place. I make take the wires from any of the coils, and combine them in such a
way that they may be used in a series, parallel or other circuit, or I may insert
resistances, or lamps in the circuits of the separated coils. There are many
advantages, and especially for experimental work, which the divided, or laminated
construction of the coils, and also of the field and armature cores, offers :-It will
enable me to obtain any desired result, in the most economical arrangement, and
combination of iron and insulated wire; and to divide the current in any way; and

page_text: in the event of damage to the coils, each coil can be quickly taken off and the
damaged coils be as quickly replaced.
I build up the commutator, or collector of my Dynamo machine, with metal
sections in any of the known ways, I arrange a special method of making the
connection between the wires of the armature; I provide a raised edge or flange
formed by projections of all the sections, at one end of the commutator, with
separate V shaped or half circular shaped grooves at the top of each section, cut
parallel to the axis of the commutator, and almost the full width of the limit of the
sections I place a screw in the centre of each of these grooves, the head of which
will enter the top of the groove. I bring the ends of the two wires one from each
of the adjacent coils, and pass one under each side of the screw, which when it is
screwed down binds the wire between itself, and the sides of the groove, and thus
makes a very tight connection, the unloosing, the screw allows each wire to be
easily withdrawn.
I arrange and fit the collecting brushes, and brush holder of my improved
Dynamo as follows:-On the end of the axle of the commutator, I fit a ring with
two extension pieces, and socket arms, and to these arms, I attach the two brush
holders suitably insulated, I make the brush holders of a stem, or rod of metal
fitted at one end into the socket arm, and free to turn under the influence of an
adjustable spiral or flat spring; the other end carries the brushes or collecting
contacts. I make the brushes of wire, or flat strip metal, and attach them to the
holder by means of binding screws only; or by clamping them with a binged
clamp and set screw I fix a stopping pin, or arm, so that when the brushes are
turned back off the commutator, by means of an insulated nut at the end of the
stem, or, rod, or by pressing the brushes direct which are provided with an
insulated cap for the purpose; the brushes are locked and kept off the commutator,
by the pin, or arm, falling or being pressed into a stop hole in the stem, reversing
this i,e, lifting the pin, or catch, allows the brushes to gear and press upon the
commutator. This is especially useful when working with gas engines, which
often reverse and turn the edges of the brushes. I fit the brush holder with a
slotted case for the brush, and a spiral spring, or weight, presses it in such a way
that the brush is fed down upon the commutator as it wears away or I fix the
brushes, to holders, pivotted to the ring on the axle, with the brushes fixed at the
ends, the brushes in this case are curved shaped, and are pressed upon the com-
mutator, by means of springs, bearing upon the holders, in such a way, that as
they wear they press upon the same part of the commutator; or I make the
holders themselves of spiral springs. This construction of brush holder, and
brushes, will feed the brush as it wears away, and allow the armature, and
commutator, to run in either direction, the brush bearing endwise or parallel to
the axis and having a little play either way is not affected by reversals; this
arrangement is especially suitable for use when the Dynamo is worked as a motor.
In some case, I provide the ring on the axle, with teeth on its outer edge, and by
means of a screw, worm, or a toothed rack, or pinion gearing I can alter the lead
of the brushes from any convenient position at or distant from the machine.
Dated this 31st day of December 1884

page_text: Improvements in Magnetic Electric Machines.
I, HENRY FRANCIS JOEL, of 44 Lavender Grove, Dalston, London, in the County
of Middlesex Electrical Engineer do hereby declare the nature of my invention for
"IMPROVEMENTS IN MAGNETIC ELECTRIC MACHINES" and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:
My Invention relates to an improved construction of Magnetic Electric Machines.
I construct a Dynamo Electric Machine or a Magnetic Electric Machino (see
Figs. 1 and 2 of my drawing, Fig. 1 a front elevation and Fig. 2 a side elevation)
with two upright field magnets M, M, bridged, or joined across by two pole
pieces N, S, the armature revolving between them, and the whole being suitably
mounted with bearings, and base plates.
I make the cores of the field magnets M, M, of a laminated construction with
wrought, cast iron, or steel plates, bars, or tubes, to prevent or neutralize as much
as possible the formation of so called "Foucault or eddy currents.
"
I fit the plates, or bars into the solid wrought, or cast iron pole pieces N. S, for
the purpose in the ends of these pole pieces, into which the ends of each
plate m, m, or bar, or a number of core plates or bars, side by side, are fitted
see Fig. 2, the whole being secured by bolts bb; this construction makes a good
magnetic connection between the core bars m, m, and the pole pieces N. S.
I make corrugated holes, or grooves in the body of the pole pieces, see C, Fig. 1,
for the purpose of concentrating the magnetic lines of force at any desired part of
the poles, and also to prevent the formation of eddy currents. I may reverse the
foregoing construction by making the pole pieces of laminated iron plates, and the
magnet cores of solid iron, fitting them together in the same way as described; or
I may make the whole of the iron magnet cores, and pole pieces, of laminated iron
plates, see Figs. 3 & 4, bars, or strips, or tubes, so that the cores m, m, and pole
pieces N. S, of the Dynamo is built up of thin strips or bars of iron, in one whole
piece or frame, see Fig. 5, or made of separate parts joined together, as in
Figs. 3 & 4, and I may insulate these thin core plates and poles, the one set from
the other, in layers, so that the completed core and poles is built up of a number
of distinct and separate magnet core frames, side by side, this is done in order, still
further to decrease the loss due to eddy currents. I connect, and join the
laminated cores and poles the one to the other, and keep them in their correct
shape, and place, by means of square bolts, b, or by stepping the ends of the one
set of bars for the other set to be fixed to, as shewn in Figs. 3 & 4, or by fixing
caps, or shoes P see Fig. 6, (a side, and an end elevation), with milled slots, over
the joints, and also by set pins.
I provide and fix one or more polar extension pieces, or plates n, Fig. 4, which
I fit between, over, or through the plates m, m, or solid pieces at the poles, these
may be made in one piece, with milled or cast grooves, or slots, as shewn

page_text: C, Fig. 1, or of thin plates, as in Fig. 4, and of any desired shape, and these
lar extension plates, or pieces, can be utilized to fix and secure the junctions, as
Fig. 4, to prevent them from shifting. I may interspace or alternate one or
ore steel plates, or bars, or tubes, in place of any of the soft iron bars m, m, or
le pieces N. S, which may become permanently magnetised. By the foregoing
scribed special construction of Dynamo machine frames I obtain several distinct
vantages oyer the usual solid construction, as follows:-
I obtain the same, or a greater degree of magnetism with my laminated cores,
on solid would sives
at C, Fig. 1, or of thin plates, as in Fig. 4, and of any desired shape, and these
polar extension plates, or pieces, can be utilized to fix and secure the junctions, as
in Fig. 4, to prevent them from shifting. I may interspace or alternate one or
more steel plates, or bars, or tubes, in place of any of the soft iron bars m, m, or
pole pieces N. S, which may become permanently magnetised. By the foregoing
described special construction of Dynamo machine frames I obtain several distinct
advantages oyer the usual solid construction, as follows:-
I obtain the same, or a greater degree of magnetism with my laminated cores,
than solid cores would give.
I concentrate the magnetism at the poles, and can retain it permanently..
I obviate to a great extent the loss due to "Foucault" currents.
The advantages in the mechanical construction are:—
Decreased weight for the same result.
The cores can be made of the best iron.
Each strip or shaped part can be cut or stamped by machinery.
Machines with narrow, or broad frames, can be readily made by decreasing or
increasing the number of the same sized plates, side by side.
The spaces between the bars allow free ventilation.
Each part is detachably attached.
.
I may use the jointing caps, P, Fig. 6, or shoes as the pole pieces, and make two
or any number of poles in that way. I may use the above laminated construction
for any shaped Dynamos, for instance of rectangular shape, such as shewn and
described, or a circular, or other curved shape, if I make a circular shaped core,
I divide the circle in two halves, with two poles, and only two joints, to make, or
I may divide the circle into a number of segments, with the junction pieces to
form the poles, the joints being made by milled slots as before described.
I may make two or any number of field magnets side by side, with pole pieces
bridging across and connecting them.
I construct the cores of my armature see Figs. 7, 8, & 9, in a manner similar to
the cores of the field magnets i.e. with laminated iron plates. A circular disc or
drum shaped armature Fig. 7, a front elevation, Fig. 8, a section, is built up of a
number of divided, and separate segmental shaped plates A. A, formed into
sections, and joined together by overlapping, and interlocking the ends of the
sections, as shewn in Fig. 9. This ring core is secured to spokes of a central
wheel W, or to two end wheels, as may be convenient, of non magnetic material,
by bolts R, fixed parallel to the axis of rotation; the same bolts holding the
sections of the core together. The segmental plates forming the armature, may be
stamped with projecting teeth or radial prolongations see a Fig. 9, at intervals
in order to bring the body of the iron core as closely as possible to the field
magnets.
I insulate these plates, and bolts, and spoked wheels and all of them, the one
from the other in order to avoid all loss from "Foucault" or eddy currents. The
same advantages I have enumerated for my field magnet cores apply equally to my
armature. I arrange and fit the insulated wire coils, for both the field magnet
cores, and the armature cores, in a special and novel manner. I wind the wire
coils E, E, beforehand see Fig. 10, field magnet coils, and Fig. 11 armature coil,
on separate bobbins, in a lathe or otherwise, and then thread or pass them over the
cores m, m or A. I may build up each field magnet M, Fig. 1 of a number of such
coils E, shewn in shaded lines, made of thin, thick square, or other shaped section,
and use thick wire coils, or coils. made of thin wire, or a combination to make
electro magnets for a series, shunt, or compound wound Dynamo Machine, of
any required resistance, I also make the coils to fit the one concentrally over
the other, as shewn in Fig. 10. It is obvious that with suitable coils any desired
combination can be made. I may interspace the coils on the field magnet cores
with. iron extension polar pieces, and I may interspace the coils on the armature,
with radial projecting and dividing pieces a¹, a¹, see Fig. 12, these latter I make to
fit over, and between the plates of the armature, and under the coils, and to be

page_text: kept in place by the coils, each succeeding coil as it is threaded on the sections of
the armature core see Fig. 7, and placed in position keeps the preceding separating
extension piece in its place. I may take the wires from any of the coils, and
combine them in such a way that they may be used in a series, parallel, or other
circuit, or I may insert resistances, or lamps in the circuits of the separated coils.
There are many advantages, and especially for experimental work, which the
divided or laminated construction of the coils, offers:-It will enable me to obtain
any desired result, in the most economical arrangement and combination of iron
and insulated wire; and to divide the current in any way; and in the event of
damage to the coils, each coil can be quickly taken off, and the damaged coils be.as
quickly replaced. I build up the commutator C, see Figs. 12 & 13, or collector of
my Dynamo machine, with metal sections in any of the known ways, I arrange
a special method of making the connection between the wires of the armature, see
Fig. 12 an end view of half a commutator, I provide a raised edge or flange formed
by projections of all the sections, at one end of the commutator, with separate
V shaped or half circular shaped grooves g. g. at the top of each section, cut parallel
to the axis of the commutator, and almost the full width of the limit of the
sections. I place a screw in the centre of each of these grooves, the head of which
will enter the top of the groove. I bring the ends of the two wires, one from each
of the adjacent coils, and pass one under each side of the screw, which when it is
screwed down binds the wire between itself, and the sides of the groove g, and thus
makes a very tight connection, the unloosing, the screw allows each wire to be
easily withdrawn. I arrange and fit the collecting brushes F, Fig. 13, and brush
holder of my improved Dynamo as follows:-In the end of the axle J, of the
commutator C, I fit a ring H, with two extension pieces, and socket arms h, h, and
to these arms, I attach the two brush holders B & B¹, suitably insulated, I make
the brush holders B & B¹, of a stem, or rod of metal fitted at one end into the
socket arm, and free to turn under the influence of an adjustable spiral D, or flat
spring D¹ the other end carries the brush or collecting contacts F.
I make the brushes of wire, or flat strip metal, and attach them to the holders
by means of binding screws only O, or by clamping them with a hinged clamp B',
and set screw 01. 1 fix a stopping pin V or arm, so that when the brushes are
turned back off the commutator, by means of an insulated nut at the end of the
stem, or rod, or by pressing the brushes direct, which are provided with an
insulated cap f, for the purpose; the brushes are locked, and kept off the com-
mutator, by the pin, see Fig. 14, or arm, falling or being pressed into a stop hole in
the stem, shewn in dotted lines, reversing this i.e. lifting the pin V, or catch, allows
the brushes to gear and press upon the commutator. This is especially useful
when working with Gas Engines, which often reverse and turn the edges of the
brushes.
I fit the brush holder B, Fig. 15, with a slotted case K, for the brush F, and a
spiral spring or springs shewn dotted, or weight presses it, in such a way the
brush is fed down upon the commutator as it wears away, or I fix the brushes
see Figs. 16 & 17, to holders B, B, pivotted at p, to the ring H, on the axle J, with
the brushes F fixed at the ends, the brushes in this case are curved shaped, and are
pressed upon the commutator C, by means of springs X, bearing upon the holders B,
in such a way, that as they wear they press upon the same part of the com-
inutator C; or I make the holders themselves of spiral springs or attach a spiral
spring D to allow the brush to give a little, this construction of brush holder, and
brushes, will feed the brush as it wears away, and allow the armature, and com-
mutator to run in either direction, the brush bearing endwise and parallel to the
axis J, and having a little play either way as shewn in diagram Fig. 18, is not
affected by reversals; this arrangement is especially suitable for use when the
Dynamo is worked as a motor. In some case, provide the ring H, on the axle J
with teeth on its outer edge, see Fig. 16, and by means of a screw, worm L, or a
toothed rack, or pinion gearing can alter the lead of the brushes from any
convenient position at or distant from the machine,

page_text: Having now particularly described, and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The construction of Magnetic Electric Machines with laminated magnet cores,
fitted into solid pole pieces or with laminated pole pieces fitted into solid magnet
cores substantially as shewn and described with reference to Figs. 1 & 2 of my
drawing.
2. The construction of Magnetic Electric Machines with poles having cross
corrugations substantially as shewn and described in reference to Fig. 1.
3. Magnetic Electric Machines in which the fields are made with two or more
separated, distinct, and complete magnet cores, and pole frames, plates, or discs
substantially as shewn and described in reference to Figs. 3, 4 & 5.
4. The construction of Magnetic Electric Machines with laminated magnet cores
and poles substantially as shewn and described with reference to Figs. 3, 4 & 6.
5. The construction of the armature cores of Magnetic Electric Machines, sub-
stantially as shewn and described in reference to Figs. 7, 8, 9, & 12.
6. The construction and arrangement of the coils of the field magnets and
armatures of Magnetic Electric Machines substantially as shewn and described with
reference to Figs. 1, 10 & 11.
7. The construction of commutators for Magnetic Electric Machines, substantially
as shewn and described with reference to Figs. 12 & 13.
8. The construction of Brush Holders and Brushes for Magnetic Electric
Machines substantially as shewn and described in reference to Figs. 13 & 14.
9. The construction and arrangement of the Brush Holders and Brushes sub-
stantially as shewn and described with reference to Figs. 15, 16, 17 & 18.
Dated this 30th day of September 1885.