Machines, and Electric Motors.
Year: 1885

page_text: Machines, and Electric Motors.
We, WILLIAM HENRY ALLEN and RICHARD WRIGHT, both of York Street
Works, Lambeth, in the County of Surrey, Engineers, and GISBERT KAPP, of
Warley in the County of Essex, Engineer, do hereby declare the nature of our
invention for "IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES, MAGNETO-
ELECTRIC MACHINES, AND ELECTRIC MOTORS" to be as follows:-
Our invention relates to Dynamo and Magneto-Electric machines, used for
generating electricity and it is also applicable to Electric Motors used for utilizing
currents of electricity, and it has more especial reference to the armature and field
magnets forming part of such apparatus.
We employ an armature wound on the Gramme or Pacinotti principle and con-
structed as follows:-The core of the armature consists of soft iron wire or soft
wrought iron discs wound or slipped on to a supporting cylinder of brass, gun
metal, cast iron or other suitable metal. This supporting cylinder is open at the
ends and its surface is provided with a number of perforations or slots giving it
the appearance of a grating bent into the shape of a cylinder.
Those bars of the grating which are parallel to the axis are placed alternately in
order that wasteful internal currents may be avoided as far as possible. To stiffen
this supporting cylinder we provide it round its exterior circumference with one or
more flanges either cast in one with it or separately attached, and we sometimes
shape the outside contour of these flanges so that they form a number of radial
spokes or horns set evenly around the circumference the tips of which enter at
certain intervals between the external coils of the winding of the armature and
thus transmit in a positive and mechanical way the driving power from the
supporting cylinder to the coils on the armature. The supporting cylinder itself
is carried by means of one or more sets of flat internal spokes springing from a
central hub which is fixed upon the axle by means of keys or screws or in any
other suitable manner. The spokes may either be cast in one with the supporting
cylinder or they may be separately attached. In the latter case we generally
provide two sets of spokes one set at each end of the cylinder and we make the
attachment by providing the cylinder with slots or grooves, parallel to the axle,
into which slots or grooves the ends of the flat spokes are made to fit. After they

page_text: are inserted an end view of the cylinder shews a number of internal segmental
spaces for the accomodation of the inner coils of the armature winding.
We place the two sets of spokes so that they are in line with each other and the
number of segmental spaces obtained will then be equal to the number of spokes
in each set. We make the spokes, preferably rectangular in cross section, narrow
in end view and in length, measured in a direction parallel to the axis, less than
half the length of the cylinder, and we thus consequently obtain openings by which
air can get to the grating of the supporting cylinder after the internal segmental
spaces are covered by the armature coils. To still further facilitate the admission
of air we sometimes subdivide each segmental space into two or more sections by
inserting into the inner circumference of the supporting cylinder one or more sets
of insulated distance pieces and thus provide additional openings between the inner
coils of the armature winding, which openings extend nearly throughout the whole
length of the supporting cylinder.
In order to allow the air admitted into and through the supporting cylinder to
pass through the core of the armature we subdivide the latter into a number of
short cylindrical rings separated from each other by narrow insulated distance
pieces and we arrange the annular air spaces so formed so that they come over the
openings in the grating of the supporting cylinder. We do not cover the whole of
the external surface of the core with winding but leave at even and regular
intervals longitudinal spaces free from winding, so that the air may escape between
the external coils and thus keep the supporting cylinder, core and winding cool.
Where we employ a supporting cylinder with horns as above described; the
longitudinal spaces in line with the horns are used for the purpose of ventilation,
and if necessary, additional spaces may be provided by intermediate insulated
distance pieces.
If we employ iron discs or short cylindrical rings of iron wire coiled on a
separate former for the armature core, only one of the flanges of the supporting
cylinder can be cast with it and we slip the discs or the made up rings on to the
cylinder, taking care to have as tight a fit as possible. The discs are slightly
insulated from each other by thin asbestos paper or a coating of insulating paint,
but in the case of wire on account of the small surface of contact, as is wellknown,
no special insulation of one wire against the other is necessary.
If we construct the core by winding soft iron wire directly upon the supporting
cylinder all the flanges may be cast in one. with the latter and to prevent some of
the iron wires entering the openings of the grating and thus losing the circular
shape necessary for the balance of the armature we lap a sheet of vulcanized fibre,
or paper or German silver or other suitable material round the supporting cylinder
before commencing to coil the iron wire on it and we cut this lining out opposite
the openings after the core is wound. Or we may block up the openings of the
grating by wedges, which we remove after the core is wound.
The outline of the discs forming the core may be either a plain circle or it may
have a number of notches placed equidistantly all round, which notches after the
core is made up, form longitudinal grooves for the reception of the outer coils of
the armature winding. This arrangement, known as Pacinotti's winding, we
consider preferable to the ordinary cylindrical core and winding known as the
Gramme winding, because the iron teeth between the coils can be made to project
outwards and very closely to approach the polar surfaces of the field magnets, by
which means the intensity of magnetism is increased.
But where from reasons of economy or through the employment of iron wire
instead of discs, or from other reasons a core on this true Pacinotti principle cannot
be used, we sometimes employ the following device for at least approximately
obtaining the benefit of projecting teeth. After the true cylindrical core is formed
and insulated we place as evenly as possible at intervals all round it longitudinal
strips of iron, each strip being either a solid bar, or a bundle of wires, or a bundle
of laminae set on edge.
The outer coils of the armature-winding we place between these strips.

page_text: To hold the latter firmly in place and also to prevent the outer coils of the
armature winding from bulging outwards under the action of centrifugal force we
bind the whole together in the usual manner by bands or hoops of insulating
material with an outer serving of thin steel wire or other suitable wire. When the
longitudinal strips are formed of solid bars or of laminae of iron we provide them
sometimes with recesses on their outer surface into which the binding hoops fit.
The object of this arrangement is to make the fastening of the strips as positive as
possible and also to allow intermediate portions of the strips to approach the polar
Surfaces of the field magnets more closely than the binding hoops.
Before commencing to wind the copper conductor upon the armature core we
insulate the latter all over, taking care not to cover up the air spaces. Special
insulation is required for the tips of the horns by which the driving force is
transmitted to the coils. The internal segmental spaces we insulate with pieces of
fibre bent into a suitable shape so as to protect the internal coils from contact with
the supporting cylinder, spokes and distance pieces. To facilitate the winding we
remove, if possible, the spokes and hubs and replace them for the time being by
short duminy spokes, leaving nearly the whole internal space of the supporting
cylinder free. After the winding is completed we take the dummies out and
roplace the spokes and hubs. The coils of winding on the armature core we join
up with each other and with a commutator or collector in the method usually
employed in continuous current machines of the Gramme or Pacinotti type.
An armature constructed as above described we can employ in combination with
field magnets consisting either of permanent steel magnets or of electro magnets
and of any suitable shape.
One arrangement of electro magnets which we find especially convenient and
cheap to manufacture is the following.
The magnets consist of a rectangular frame of straight wrought iron slabs bolted
together and of sufficient thickness to allow of the boring out of the polar cavity
in the middle of the two longer opposite slabs. We place this frame horizontally
and support it at either end on a cast iron rectangular frame which also serves for
the support of the bearings for the armature. The latter are placed on the two
opposite sides of the rectangle which are at right angles to the sides supporting
the magnets.
The magnets are excited by coils of insulated copper wire wound on separate
metal formers and slipped over the slabs.
In another arrangement, when it is not important to minimise the weight of the
machine, we may employ cast iron field magnets cast in one piece with the bedplate
and supporting standards for the bearings of the armature spindle.
In this case we place the magnet cores vertically and we may either employ a
single magnet of the horse shoe form having its yoke in the bedplate and separate
pole pieces bolted to the end of the cores and bored out to receive the armature;
or we may employ such a magnet with pole pieces cast on, but so shaped as to
permit of the formers carrying the field magnet coils being slipped over them; or
we may employ a double horseshoe magnet having four cores, one yoke in the
bedplate and the other yoke on the top. In order to be able to place the field
magnet coils on to the cores we divide the magnet casting either on a horizontal
plane through the pole pieces or we make the top yoke removeable. In the former
case the two halves of the magnet casting are held together by segmental side
pieces forming part of the pole pieces and bolted thereto. These side pieces also
serve to increase the active length of the polar surface and at the same time form
a support for the two top formers and exciting coils. Similar side pieces we may
also employ in the case of the top yoke being separately bolted to the magnet
castings.
In another arrangement, which is especially suitable for slow speed machines, we
employ an arrangement of field magnets, having two or more pairs of poles. In
this case we place the magnet cores radially on the outside of the armature and
join their extremities by one common yoke in the form of a polygon. The exciting

page_text: coils are also wound on formers and these are slipped over the cores from the inside.
In order to be able to do this the diameter of the polar cavity must be sufficient
to allow the introduction of the coils. The magnet cores and the polygonal yoke
common to all may be cast in one piece and one of the end bearings for the
armature set in curved arms springing from the yoke may also be part of the same
casting. The other bearing for the armature spindle must however be removeable
for the purpose of admitting the armature. The formers carrying the exciting
coils are fastened to the cores by means of screws, wedges, or in any other suitable
manner.
Or in a modified arrangement of multipolar field magnets, which is equally
applicable to cast iron and wrought iron magnets, we employ a common yoke of
cylindrical form and separate magnets bolted to the inner surface of the cylinder
and extending towards the centre. The length of these magnets in a radial
direction is such that between their inner ends sufficient room is left for the
armature and we sometimes widen out the inner ends into poles of somewhat larger
surface than the cross sections of the magnet core proper. We provide each of the
magnet cores with a coil or coils of insulated wire of suitable shape by which the
said cores are excited.
The arrangements of field magnets last described are particularly applicable to
dynamo machines the armatures of which have to be driven direct from the shaft
of a prime mover without intermediate gearing or belting. In this case we bolt
the bedplate of the prime mover direct to the lower part of the polygonal or
cylindrical yoke and obtain a perfectly self contained arrangement of prime mover
and dynamo.
The armatures and field magnets described may be applied to electric motors for
giving out motive power, by passing through them in the proper direction currents
of electricity generated by apparatus of a similar or other suitable kind.
EDWARDS & Co.,
Agents for the Applicants. 30

page_text: Machines, and Electric Motors.
We, WILLIAM HENRY ALLEN and RICHARD WRIGHT, both of York Street Works
Lambeth in the County of Surrey Engineers, and GISBERT KAPP, of Warley in the
County of Essex, Electrician, do hereby declare the nature of the said Invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
Our invention relates to Dynamo and Magneto Electric Machines used for
generating electricity and it is also applicable to Electro Motors used for utilizing
currents of electricity and it has more especial reference to the armature and field
magnet or magnets forming part of such apparatus. We employ an armature
wound on the Gramme or Pacinotti principle and constructed as follows. The core
of the armature consists of soft iron wire or of soft wrought iron discs wound or
slipped over a supporting cylinder of brass, gun metal, cast iron or other suitable
metal. This supporting cylinder is open at the ends and its surface is provided
with a number of perforations, which when large give it the appearance of a
grating bent into the shape of a cylinder. In some cases these openings are small
rectangular slots cut or cast out of the surface of the supporting cylinder and placed
between internal circular ribs. To stiffen the supporting cylinder we provide it
externally with one or more flanges either cast in one piece with it or else separately
attached and we sometimes shape the outside contour of these flanges so that they
form a number of radial horns or spokes set evenly around the circumference the
tips of which horns are provided with insulating ferrules and enter at certain
intervals between the external coils of the winding of the armature and thus
transmit in a positive and mechanical way the driving power from the supporting
cylinder to the coils on the armature. The supporting cylinder itself is carried by
means of one or more sets of flat internal spokes springing from a central hub
which is fixed upon the axle by means of keys or screws or in any other suitable
manner. The spokes may either be cast in one with the supporting cylinder or
they may be separately attached.
In the latter case we generally provide two sets of spokes, one set at each end of
the cylinder and we make the attachment by providing the cylinder with slots or
grooves parallel to the axle-into which slots or grooves the ends of the flat
spokes are made to fit.
After they are inserted an end view of the cylinder shews a number of internal
segmental spaces for the accommodation of the inner coils of the armature winding.
We place the two sets of spokes so that they are in line with each other, and the
number of segmental spaces obtained will then be equal to the number of spokes in
each set.
We make the spokes perfectly rectangular in cross section narrow in end
view and in length measured in a direction parallel to the axis less than half the
length of the cylinder and we thus consequently obtain openings by which air
can get to the grating of the supporting cylinder or to the space between the ribs
after the internal segmental spaces are covered by the armature coils. To still
further facilitate the admission of air we sometimes subdivide the winding in each

page_text: segmental space into two or more sections by inserting into the inner circumference
of the supporting cylinder one or more sets of insulated distance pieces and thus
provide additional openings between the inner coils of the armature winding, which
openings extend nearly throughout the whole length of the supporting cylinder.
In order to allow the air admitted into the supporting cylinder to pass through
the core of the armature we subdivide the latter into a number of short cylindrical
rings separated from each other by narrow insulated distance pieces or by the
flanges on the outside of the supporting cylinder above described and we arrange
the annular air spaces thus formed so that they come over the openings in the
grating or over the rectangular slots in the surface of the supporting cylinder. We
do not cover the whole of the external surface of the core with winding but leave
at regular intervals longitudinal spaces free from winding so that the air may
escape between the external coils and thus keep the supporting cylinder, the core
and the winding cool.
If we employ iron discs or short cylindrical rings of iron wire coiled on a separate
former for the armature core;-only one of the flanges of the supporting cylinder
can be cast with it and we slip the discs or the made up rings on to the cylinder,
taking care to have as tight a fit as possible. The discs are slightly insulated
from each other by thin asbestos paper or a coating of insulating paint but in the
case of wire we find that no special insulation of one wire against the other is
necessary.
If we construct the core by winding soft iron wire direct upon the supporting
cylinder all the flanges may be cast in one with the latter and to prevent some of
the iron wires entering the openings of the grating and thus losing the circular
shape necessary for the balance of the armature we lay a sheet of vulcanized fibre,
paper, or German silver or other suitable material round the supporting cylinder
before commencing to coil the iron wire on it and we cut the lining out opposite
the openings after the core is wound.
Or we may block up the openings of the grating by wedges temporarily, which
we remove after the core is wound.
If the supporting cylinder instead of being of the character of a grating proper
with large openings is formed as a nearly continuous surface having only narrow
rectangular slots as above described, we preferably place these slots near to or
between the external flanges and in that case these flanges serve to protect the iron
wire which forms the core from falling into the slots during the process of coiling.
To prevent electrical continuity on the external circumference of the armature core
we cover the surface of the supporting cylinder and the sides of the flanges with
asbestos paper, fibre, a coating of insulating paint or other suitable insulating
material and we by these means obtain an armature core subdivided into two or
more short lengths electrically insulated from each other. After the core has been
coiled we insulate it with tape, fibre, varnished paper, or other suitable material
taking care not to cover up the ventilating openings.
The internal segmental spaces we insulate each by a sheet of insulating material
bent into the shape of a trough or channel into which the inner turns of the
winding are laid, the said trough or channel bearing against the bars of the grating
or the internal circular ribs, by which arrangement air is permitted to flow to the
back of the internal wires and through the core. The driving borns are insulated
with fibre ferrules; and distance pieces of fibre, wood, or other suitable material
are employed to space the external winding out into groups between which the air
passing through the core can escape.
To facilitate the winding of the armature we remove, if possible, the spokes and
replace them for the time being by strips of wood placed parallel to the axis on
the inside of the supporting cylinder, acting as short dummy spokes so as to define
the position of the internal wires but otherwise leaving the internal space free for
the convenience of winding.
After the winding is completed we take the dummy spokes out and replace the
real spokes and hubs. The individual coils forming the winding on the armature

page_text: core we join up with each other and with a commutator or collector in the method
usually employed in continuous current machines of the Gramme or Pacinotti
type.
In the accompanying drawings Figure 1 is a longitudinal section through one of
our armatures showing the supporting cylinder S S having two circular end
flanges and three intermediate flanges D1, D2, D3, cast in one piece.
The cylinder is supported on the spindle by the hubs H¹ H³ with the arms A¹ A²
fitted into suitable slots or grooves 81, 81, 82, 83, at the ends.
V, V, are annular ventilating spaces placed over the openings of the cylinder or
bent grating and L L is a sheet of metal lapped round the cylinder to prevent the
wire falling into the openings.
The plates P P serve to keep the wire from falling into the annular spaces V, V.
Figure 3 shows a cross section through one half of the armature. Figure 2 shows
a longitudinal section through a modified arrangement of our armature where the
annular ventilating spaces are arranged at the side of the flanges D, D, D,
plates P P being used as before to prevent the iron-wire forming the core from
falling into these spaces. G, G, is the surface of the supporting cylinder shaped as
a grating and LL are sheets of metal or fibre lapped round the cylinder to prevent
the iron wire falling into the openings of the grating. The end plates E E are in
this case separately attached. The shaded spaces W W between the flanges
represent the iron wire core of the armature and d d represent the projections or
driving horns forming part of the flanges D, D. The winding of insulated copper
wire is not shewn in order not to complicate the drawing.
Figures 4 and 5 show another modification of our armature. Here we place the
external flanges in pairs D¹, D¹, and D³, D³, and utilize the spaces between them
V¹, V¹, and V³, V2, for purposes of ventilation as already described with reference
to figures 1 and 2.
In another modified arrangement we make the flanges D circular in outline with
small pegs d cast on as shewn in the upper halves of figures 6 and 7 and we in
this case dispense with the plates P, P, as the flanges D themselves serve to keep
the iron wire from falling into the ventilating spaces V¹, V1, V2, V2
Sometimes we arrange the pegs & between the flanges D₁, D₁, D2, D2, as shewn
in the lower halves of figures 6 and 7.
.
In some cases we omit all these openings in the supporting cylinder which are
between the flanges E D', D¹ D2 and D E (figure 6) and we retain only the
openings O¹ and O' which are between the flanges D¹, D¹, and D' D³. In this
case the lapping of thin metal or fibre L L becomes unnecessary.
Figure 8 shows a longitudinal and Figure 9 a cross section through an
armature made according to this modification. The supporting cylinder is cast in
one piece with its end Hanges E, E, and ventilating flanges D¹ D¹, D² D². The
driving pegs
placed between the ventilating flanges may either be separately
attached or form part of the same casting. Three internal flanges G G G serve to
keep the inner coils of the winding of insulated copper wire off the internal surface
of the supporting cylinder and air is thus admitted to the openings 01 02. This
arrangement is more clearly shewn in figure 10 which represents a cross section
through our armature, the section being taken through the annular space included
between one pair of ventilating flanges. Figure 11 represents part of the external
surface of the armature after completion. H is the central hub and A. A are the
supporting arms keyed to the spindle and fitting into slots ss at the ends of the
supporting cylinder, also shown in figure 1. GG are internal circular ribs.
winding of insulated copper wire is shewn at C C and the inner coils are placed
into a trough or channel T made of insulating material and resting against the
ribs G G. Air is thus admitted between these troughs T and the inner surface S S
of the supporting cylinder and finally through the openings O into the annular
ventilating spaces W and out at the external periphery by the openings O.
J represents the internal insulation of the core of the armature. F the fibre or
wood ferrules by which the driving horns or pegs & are insulated and K K the
The

page_text: additional distance pieces of fibre wood or other suitable material by which the
external winding of insulated copper wire is spaced out into groups. The ferrules
and distance pieces are held in place by the usual binding hoops B, B.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what
we claim is
1. The use of a perforated cylinder for supporting an armature coil consisting
of iron plates or iron wire coils substantially as and for the purposes described and
shewn in the drawings.
2. The cylindrical grating or internal circular ribs for the purpose of keeping
the internal portion of the armature winding a small distance from the inner
surface of the armature core in order to allow access of air, substantially as
described and shewn in the drawings:
3. The longitudinal air spaces between the corresponding arms A¹ A' sub-
stantially as described and shewn in the drawings.
4. The external flanges D in combination with annular ventilating spaces V and
driving horns d substantially as described and shewn in the drawings.
5. The construction of armatures substantially as described and shewn in the
accompanying drawings.
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