IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES OR ELECTRIC GENERATORS
Year: 1883

page_text: LETTERS PATENT to Sebastian Ziani de Ferranti of N° 5 Stanwick Road
West Kensington, Electrician and Alfred Thompson of N° 3 Fenchurch
Avenue in the City of London. Electrician for an Invention of "IMPROVE-
PROVISIONAL SPECIFICATION left by the said Sebastian Ziani de Ferranti
and Alfred Thompson at the Office of the Commissioners of Patents on the
28th July 1883.
SEBASTIAN ZIANI DE FERRANTI of N° 5 Stanwick Road West Kensington
Electrician and ALFRED THOMPSON of N° 3 Fenchurch Avenue in the City of
London Electrician "IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES OR ELECTRIC
GENERATORS
כן
In the construction of dynamo electric machines in order to obtain safer insula-
tion between the iron cores and the electric conductors wound around them we
give to the sides of the cores a coating of enamel or like insulating material and if
the cores are cast in one piece with the side frames the inner face of the frame may-
also be similarly enamelled.
When the electric conductors used for exciting the several magnets in each circle
of magnets of a dynamo electric machine aro metallic bars wound in a zig zag
manner in and out between the magnet cores we insulate the conductors from the
cores by interposing between them rods of insulating material and the several
conducting strips which lie side by side we. insulate one from the other by small
studs of insulating material carried in small corresponding depressions in the sides
of the conducting strips and made to project therefrom so as to keep the metallic
bars at a distance the one from the other.
When the conductor is wound separately in one continuous coil around each
magnet core the several coils may similarly be insulated one from the other and
from the cores.
When the conductor of the armature is a zig zag conductor as described in our
former Patent dated 18th July 1882 N° 3419 in place of forming it of one single
bar or of several convolutions of one single strip as described in the specification of

page_text: that Patent we form it of several strips overlying one another and insulated the
one from the other so as to avoid Foncault currents-all the strips being coupled
together at their ends so as there to form one conductor.
In the same way if instead of the conductor being formed of a single zig-zag bar
it is composed of several coils each composed of a metallic strip wound into a coil
of any suitable shape instead of making each coil of one single flat strip we form
it of two or more overlying strips insulated from one another and connected at
their ends.
In some cases also in addition to dividing the conductor whether a zig-zag coil
or other suitable shape into overlying layers as above described we subdivide each
strip into two or more narrower strips lying side by side.
When a zig-zag armature is formed of overlying strips as above described each
strip may be made to start and finish at a different point of the circumference of
the wheel to the other strips so that the leading off of the current from the
zig-zag conductor may be effected at numerous points around the circumference of
the wheel instead of at one point only. To facilitate the taking off of the current
from the several strips we surround the body of the wheel with a ring of metal
insulated from it. In the outer circumference of this ring we form recesses for the
inner bends or loops of the zig zag conductor to lie in.
Each strip is preferably made to end. close to the point from which it starts.
One end rests in one of the recesses formed in the metallic ring above mentioned
and so is brought into contact with the ring the other end is in contact with the
metallic pin or rivet used for holding one of the inner bends or loops of the
conductor into this recess.
:.
The pin or rivet is carried by arms which stand out from metal ring discs
surrounding the boss of the wheel and insulated from it.
These discs each carry as many arms as there are metallic strips in the
conductor. If the zig-zag is formed-with more bends-or-loops in it than there are
metallic strips in the conductor the remaining pins or rivets used for holding the
remaining inner bends or loops of the zig-zag to the wheel are carried by arms
standing out from the body of the wheel and these pins or rivets we surround with
insulating material wo also interpose insulating material between the insulated
metal ring and the inner bends of tho zig zag which are held in by these insulated
rivets.
The insulated metal ring we couple by numerous bolts to an insulated metal
ring surrounding the axle. One of the insulated discs we also couple to a similar
insulated metal ring on the axle and from these rings on the axle the current is
led away by rubbers in the usual way.
This construction of armature is especially applicable for machines of large size.
The magnets of such machines we wind with a strip conductor or conductors in
the way herein described.
To allow of the driving belt used for driving the machine being tightened when-
ever required we make the machine moveable upon the bed plate which carries it
and in order to connect the terminals in the machine with the fixed terminals on
the base plate we use fixed blocks with sliding conducting bars which may be
nipped in the blocks by means of screws.
In place of the inner bends or loops of the zig-zag being made to rest in recesses
in an insulated metal ring surrounding the wheel they may rest in recesses in
the circumference of the body of the wheel itself in this case one of the contact
rings around the axle would be uninsulated.
If in place of making the armature of a conductor of a zig-zag form it is
composed of separate coils carried around the circumference of a wheel and each
coil composed of a metallic strip or strips similar methods of connection may be
employed. The outer ends of each coil may be in contact with an insulated metal
ring surrounding the wheel or with the wheel itself, the inner ends are led to the
pins or rivets used for holding the coils.

page_text: In this way the current would be led off direct from each coil without passing
through the other coils.
Other ways than that above described may be adopted for working the several
coils in parallel that is each independent of all the others.
When it is desired to connect the coils in series the alternate coils are wound in
opposite directions as heretofore and in order to afford a ready means of passing
the current from one coil, to another we carry pairs of the coils by insulated
segments held to the circumference of the wheel. Each segment may be somewhat
of a dovetail form and be gripped and held between two divisions of the body of
the wheel. The inner ends of the two coils carried by each segment would be in,
contact with the pins or rivets which hold the coils to the segments. The outer
ends of the coils would be secured in any convenient manner to the outer ends of
the adjoining coils carried by other segments on either side.
The whole of the coils need not be so coupled in series-the current might be
led off direct from each pair of coils or from every two three or more coils
and this can very readily be done in. ways similar to those herein before
described.
In a similar way if when a zig-zag conductor is used it is desired that the
current should not pass through the complete zig-zag but only through half or a
third or other subdivision of it each subdivision may be carried by a separate
segment and the current be led off from the several segments in the ways
described.
To carry off the current from each contact ring on the axle we employ a metal
bar curved at one end to rest on the ring and at the other end forked to embrace
the terminal pin or bolt which is fixed to tho frame of the machine or it may at
this end be made of a spherical form and rest in a round hole in the terminal bolt.
The bolt we form with an arm standing out from it and we connect this arm to
the bar by a spring this holds the curved end of the bar always down on to the
ring on tho axle-we also connect the curved bar to the arm by thin strips or
strands of copper to serve as conductors.
When there are two contact rings side by side on the axle in proximity to one
another one pin or bolt may carry the two curved bars for resting on the two
rings. In this case the arm by which one bar is carried would be in metallic
contact with the pin or bolt whilst the other arın is carried by a tube surrounding
the pin or bolt and insulated from it but in contact with the metal frame of tho
machine.
In the specification of a former Patent granted to us N° 3950 in the year 1882
we described a continuous current dynamo electric machine in which a series of
insulated radial conductors were rovolved in a magnetic field and in which
stationary rubbers were used to bear against these radial conductors near their
outer ends as well as other rubbers to bear against the conductors near their inner
ends so as to form a zig-zag circuit. According to our present invention we do
away with the rubbers used to bear against the radial conductors near their outer
ends and we connect the outer ends of all the conductors to a surrounding ring or
tyre leaving only the inner rubbers which are near to the axis. With this
construction there will be as many rubbers as there are magnets in each magnet
circle.
The alternate rubbers may be on opposite sides of the radial conductors and the
rubbers on one side may all be carried by a metallic ring whilst the rubbers on
the opposite side are carried by another metallic ring so that the whole current
may be taken off from these rings.
We also form a continuous current machine with fixed magnets wound with
strip conductors as herein described and with a helix of either the Gramme or the
Siemens type but with each of the coils thercon separate and independent the one
from the other. The two ends of each coil we connect to two diametrically
opposite bars on a commutator in the case of the Siemens type being used and in
the case of the Gramme type we connect the beginning of one coil to a bar of the

page_text: commutator and the end to the beginning of a diametrically opposite coil on the
armature whose end would in turn be connected to a diametrically opposite
commutator bar. Half the armature coils may be connected to a commutator at
one end of the spindle and the remaining half to one at the other end of the
spindle or both commutators may be put at one end.
A greater number of commutators might also be used if desired. The bars of
these commutators may be set somewhat spirally around the spindle.
Two contact blocks are made to rest against opposite sides of each commutator
and they are made of a width to be simultaneously in contact with several of the
commutator bars.

page_text: former Patent dated 18th July 1882 N° 3419 in place of forming it of one single
bar or of several convolutions of one single strip as described in the Specification of
that Patent we form it of several strips overlying one another and insulated the one
from the other so as to avoid Foucault currents-all the strips may be coupled
together at their ends so as there to form one conductor.
We prefer however that each of the overlying strips should be made to start and
finish at a different point of the circumference of the wheel to the other strips so
that the leading off of the current from the zigzag conductor may be effected at.
numerous points around the circumference of the wheel instead of at one point
only. To facilitate the taking off of the current from the several strips we
surround the body of the wheel with a ring of metal insulated from it. In the
outer circumference of this ring we form recesses for the inner bends or loops of the
zigzag conductor to lie in.
Each strip is preferably made to end close to the point from which it starts.
Ono end rests in one of the recesses formed in the metallic ring above mentioned
and so is brought into contact with the ring the other end is in contact with the
metallic pin or rivet used for holding one of the inner bends or loops of the
conductor into this recess.
The pin or rivet is carried by arms which stand out from metal ring discs
surrounding the boss of the wheel and insulated from it.
These discs each carry as many arms as there are metallic strips in the conductor.
If the zigzag is formed with more bends or loops in it than there are metallic
strips in the conductor the remaining pins or rivets used for holding the remaining
inner bends or loops of the zig-zag to the wheel are carried by arms standing out
from the body of the wheel and these pins or rivets wo surround with insulating.
material we also interpose insulating material between the insulated metal ring
and the inner bends of the zig zag which are held in by these insulated rivets.
The insulated metal ring, we couple by numerous bolts to an insulated metal ring
surrounding the axle. One of the insulated discs we also couple to a similar
insulated metal ring on the axle and from these rings on the axle the current is
led away by rubbers in the usual way.
This construction of armature is especially applicable for machines of large size.
The magnets of such machines we wind with a strip conductor or conductors in the
way herein described.
Figure 7 shews a diagram view of a zig zag coil armature formed from four
separate strips of copper which start and end at a different point of the circumference
of the wheel to the other strips the armature might however be made up of other
number of strips if desired.
The several layers of copper strips of which the zig-zag coil is composed are
insulated from one another by insulating material interposed between them. The
insulating material may advantageously be composed of paper that has been
treated with cupra ammonium and afterwards painted with asbestos paint but it
might be of other suitable tough insulating material.
A is an insulated metal ring passing around the circumference of the armature
wheel. In its outer circumference are recesses for the inner bends of the zig-zag
coil to lie in.
B are rivets by which the inner bends of the zig zag coil are held inwards against
the ring A.
Each metallic strip of which the zigzag coil is composed is at one end put into
metallic connection with the ring A and the other with one of the rivets B. The
four strips of which the zig-zag coil is shewn to be constructed are indicated by
four lines, one a full line, and the other three by varied forms of dotted lines; the
layers of insulated material interposed between them are not shewn.
One of the strips commences on the radial line N° 1 being there in contact with
the insulated metallic ring A and terminates at the rivet B which is on the same
radial line.

page_text: In a similar way another of the strips begins and ends on the radial line 2.:
another on the radial line 3, and the fourth on the radial line 4.
⋅
The rivets B which hold, the remaining bends of the zig-zag coil are insulated
from the coil and these bends likewise have insulating material interposed between
them and the metallic-ring A.
The construction of the wheel which carries the zig-zag coil is shewn on sheet 3
Figures 8, 9. 10 11. 12 and 18. C is the axle of the machine.
D are two halves or divisions of the wheel fixed upon it; around their
circumference is a groove in which the ring A is carried-the insulating material
interposed between the ring and the wheel is indicated by a broad black line.
Each half or division of the wheel has radial projections D' standing out from
it as shewn at Figures 8 and 9. The rivets B which are passed through these
radial projections have insulating material interposed between them and the zig-
zag coil. The four other rivets B which are to be in metallic connection with the
conductors of the coil are carried by radial projections E¹ (see Figures 10 and 11)
from rings E which are fixed on the two opposite sides of the wheel as shewn at
Figures 12 and 13.
The two halves or divisions of the wheel D are shown separately at Figures 8-
and 9 and the rings E at Figures 10 and 11.
Cylindrical distance pieces are also placed around these rivets to keep the'
arms E¹ of the two rings E at the proper distance apart one from the other. The
distance pieces around the other rivets would be of insulating material.
At Figures 12 and 13 are shewn a transverse section and end view of the wheel
complete.
The ring A is-by a series of insulated bolts F coupled to a metallic cylinder G
which surrounds the axle and which is insulated from it as shewn at Figure 12.
One of the rings E is likewise by a similar series of bolts coupled to another"
insulated metallic cylinder G* which surrounds the axle on the opposite side of the
wheel. The current is conveyed away from these two insulated metallic cylinders
by rubbers or brushes.
i
At Figures 14 is shown a rubber suitable for conveying away. the current from
one of the cylinders G. It is composed of two blocks H H* which embrace the
cylinder. One block H has two pins. I projecting from it which pass freely through.
holes in the other block H*. Nuts J are screwed on to the ends of the pins.I and
bear against the ends of a spring blade K which at its centre is fixed to the top of
the block H* so that by means of the nuts the two blocks may be made to hold
the cylinder G between them with any required degree of pressure. The two:
blocks are likewise coupled together by flexible conducting strips of copper K* and.
these are coupled to one end of a metallic stud L which is carried by the framing
of the machine and which as shewn at Figure 14 is formed to serve as one of the
terminals of the machine. Insulating material is interposed between the stud and
the framing of the machine as shewn by black lines at M.
The block H has also a short stud projecting from it the end of which is some-
what of a spherical form-it enters a hole in the end of the stud¸ L.
In place of the inner bends or loops of the zig-zag armature being made to rest
in recesses in an insulated metal ring surrounding the wheel they may be made to
rest in recesses in the circumference of the body of the wheel itself. In this case
one of the contact rings around the axle would be uninsulated.
'
If in place of employing a zig-zag bar as the conductor of the armature the
armature is composed of a number of separate coils ranged around the circumference
of the armature wheel in place of forming each coil from a single metallic strip we
form it of two or more overlying strips insulated from one another and connected
at their ends.
In some cases also in addition to dividing the conductors into overlying layers
as above described we subdivide each strip into two or more narrower strips placed
side by side.
:
:
-

page_text: When the zig-zag armature is composed of separate coils carried around the
circumference of a wheel the wheel may be built up and the current carried off in
a similar manner to that above described.
The outer ends of each coil may be in contact with an insulated metal ring
surrounding the wheel or with the wheel itself, whilst the inner ends may be in
contact with the pins or rivets used for holding the coils.
In this way the current would be led off direct from each coil without passing
through the other coils.
Figure 15 shews a front view partly in section and Figure 16 a cross section of
an armature so built up from separate coils and in which the current is led off
direct from each coil.
The outer end of each coil is in metallic connection with the insulated ring A
and the inner end of each coil is in metallic connection with the rivet B which
holds the inner bend of the coil up to the ring A. The rivets are uninsulated.and
are secured in radial projections from the two parts of which the body of the wheel
is composed. One of the cylinders from which the current is conveyed away is in
metallic connection with the axle, the other cylinder is insulated from the axlo and
coupled to the insulated ring A as shewn.
Other ways than that above described may be adopted for working the several
coils in parallel that is each independent of all the others.
When it is desired to connect the coils in series the alternate coils are wound in
opposite directions as heretofore and in order to afford a ready means of passing.
the current from one coil to another we cause pairs of the coils to rest against
insulated segments placed around the circumference of the wheel and we hold
the coils by rivets passed through other insulated segments in the manner shown
at Figures 17 and 18.
IT.
The inner ends of the two coils carried by each segment would be in contact with
the pins.or rivets which hold the coils to the segments. The outer ends-of-the coils-
would be in contact with the segments of the ring A, which are insulated from one
another.
As will be seen by these figures the ring A in place of being one continuous
undivided ring is divided into segments each having in its outer circumference two
recesses to receive the inner bends of two of the coils, and the rivets B in place of
being fixed to radial projections upon rings E are fixed. to segments of such rings,
each segment carrying two of the rivets.
The segments are formed with feet or projections standing out from them which
are embraced by grooves formed in the two parts or divisions of the wheel as shewn
at Figure 18.
The segments into which the rings E are divided are set so as to break joint or
come intermediate of the segments into which the metallic ring A is divided.
In this way the outer ends of the two coils resting against any one of the
sections into which the ring A is divided will be in metallic connection one with
the other whilst the inner end of the second of these coils will be in metallic
connection with the inner end of the next succeeding coil through the rivets B aud
insulated segments E.
The current is conveyed away from one of the segments into which the ring A
is divided. This segment may be made to extend nearer to the centre of the wheel
than the other segments as shewn at Figure 17 and it is divided into two parts
by a radial division--the two parts are insulated the one from the other.
One part is bolted to an insulated cylinder surrounding the axle on one side of
the wheel and the other part to an insulated cylinder surrounding the axle on the
other side of the wheel and the current is led off from these two cylinders.
The whole of the coils need not be so coupled in series the current might be led
off direct from each pair of coils or from every two three or more coils.
When the current is to be led off from each pair of coils the ring A is divided

page_text: into as many insulated segments as there are coils, whilst the ring E is divided
into half as many segments.
This construction is shown at Figure 19. Every alternate segment is by a
bolt: H put in metallic connection with an insulated cylinder G surrounding tho
axle on one side of the wheel-the remainder are similarly.coupled by bolts to
an insulated metallic cylinder G+ on the opposite side of the wheel as shewn at
Figure 18.
In this way the current is led off from the outer ends of the two coils of each
pair of coils.
The manner in which we prefer to form each coil is shewn at Figure 20 it is
made up of three overlying bands of copper insulated from ono another and then
wound into a coil of the form shewn.
Toughened paper covered with asbestos paint may advantageously be used for
insulating the three conducting strips one from the other whilst between the
several turns or coils into which such compound strip is wound we prefer to
interpose a strip of the material known as vulcanized fibre.
At Figuros 21 and 22 we have shown how each of the coils of the armature may
be in two divisions insulated from one another and how pairs of such compound
coils may be coupled in pairs and the pairs coupled up in series.
In this case the ring A is not only divided into half as many segments as thero
aro double coils but each segment is also divided into two parts insulated from one
another as shown at Figure 22. The segments on one side of the wheel are set so
as to broak joint with the segments on the other side of the wheel.
The inner ends of the two coils of each compound coil are coupled together and
insulated from the rivets B. The outer ends of the coils are in contact with the
metal segments A against which they rest. In this way the current entering at
the outer end of one coil passes through that coil and to the inner end of the coil
which lies beside it then from the outer end of this second coil through one of the
segments A to the outer end of the next coil and so on.
When the conductor of the wheel armature is of a zig-zag form in place of being
in coils and it is desired that the current should not pass through the complete
zig-zag but only through half or a third or other subdivision of it each subdivision
may be carried by a separate segment and the current be led off from the several
segments in the ways described.
To allow of the driving belt used for driving the machine being tightened
whenever required, we make the machine movable upon the bed plate which
carries it, and in order to connect the terminals of the machine with the fixed
terminals on the base plato, we use fixed blocks with sliding conducting bars
which may be nipped in the blocks by means of screws. This arrangement is
shewn at Figures 23 and 24.
In these Figures A is the bed plate.
B is the bed of the machine.
C the nut on the under side of the bed.
D

page_text: bar always down on to the ring on the axle-we also connect the curved bar to
the arm by thin strips or strands of copper to serve as conductors.
When there are two contact rings side by side on the axle in proximity to one
another one pin or bolt may carry the two curved bars for resting on the two
rings. In this case the arın by which one bar is carried would be in metallic
contact with the pin or bolt whilst the other arm is carried by a tube surrounding
the pin or bolt and insulated from it but in contact with the metal frame of the
machine.
Figures 25 to 32 shew various views of three forms of contact mechanism
constructed as above described. In these Figures the circle marked A indicates a
metallic ring from which a current is to be conveyed away.
B is a metal bar curved at one end so as to embrace this ring, and at the other
'end forked to embrace a fixed pin ör bolt E or else made of a ball shape to enter a
hole in a fixed bar or bolt projecting from the frame of the machine.
C is a spring for drawing the curved bar B towards the contact ring A.
Dare flexible bands of copper for conveying the current from the curved bar B
to the bar or pin or bolt E which forms a terminal of the machine.
In each of the above constructions as well as in the construction shewn at
Figures 14 the curved bar which rests upon the metallic contact ring on the axlo
is quite freo to adapt itself to the surface of this ring and good contact is thereby
ensured.
In the Specification of a former Patent granted to us N° 3950 in the year 1882
we described a continuous current dynamo electric machine in which a series of
insulated radial conductors wero revolved in a magnetic field and in which
stationary rubbers were used to bear against these radial conductors near their
outer ends as well as other rubbers to bear against the conductors near their inner
ends so as to form a zig zag circuit. According to our present Invention we do
away with the rubbers used to bear against the radial conductors.near. their outer
ends and we connect the outer ends of all the conductors to a surrounding ring or
tyre leaving only the inner rubbers which are near to the axis. With this
construction there will be as many rubbers as there are magnets in each magnet
circle.
The alternate rubbers may be on opposite sides of the radial conductors and the
rubbers on one side may all be carried by a metallic ring whilst the rubbers on the
opposite side are carried by another metallic ring so that the whole current may
be taken off from these rings.
Figure 33 shews an end view and Figure 34 a longitudinal section of a
continuous current machine constructed as above described. In general form and
appearance it is similar to machines heretofore constructed by us.
A are the circles of magnets, B the axle, C the wheel formed of radial con-
ductors these are all insulated from one another except at their outer ends where
they are all united to a metallic tyre D. The inner ends of the radial conductors C
have projections C standing out from them on either side of the wheel.
Rubbers E carried by the two end frames of the machine are made to bear
against the ends of these projections. Alternate rubbers are on opposite sides of
the radial conductors and there are half as many rubbers on each side as thero are
magnet poles.
Figure 35 shews a face view of the wheel of radial conductors.-Figure 36
shews a diagram view of the same wheel with the positions of the magnet pales
shewn by dotted lines. Alternate poles are of opposite polarity-the directions of
the currents induced in the radial conductors as they are carried past the magnet
poles are indicated by the arrows.-Figures 37 and 38 shew a face view and cross
section of one set of rubbers. One set of rubbers is in metallic connection with an
insulated terminal F and the other set of rubbers with another insulated terminal G
as shown at Figure 34.
..We also form a continuous current machine with fixed magnets wound with

page_text: strip conductors as herein described and with a helix of the Gramme type but
with each of the coils thercon separate and independent the one from the other.
In the case of the Gramme type we connect the beginning of one coil to a bar of
the commutator and the end to the beginning of a diametrically opposite coil on
the armature whose end would in turn be connected to a diametrically opposite
commutator bar. Half the armature coils may be connected to a commutator at
one end of the spindle and the remaining half to one at the other end of the
spindle, or both commutators may be put at ono end."
-
A greater number of commutators inight also be used if desired. The bars of
these commutators may be set somewhat spirally around the spindle.
Two contact blocks are made to rest against opposito sides of each commutator
and they are made of a width to be simultaneously in contact with several of the
commutator bars.
Figures 30 and 40 shew an end view and longitudinal section of a continuous
current machine having an armature of the Gramme type-Figure 41 is a
horizontal section of the machine and Figure 42 a diagram view of the armature
and commutator.
A B are the two magnet poles, C is the armature of the Gramme type-D the
commutator bars which are ranged together so as to form a cylinder around the
axle E as is usual.
FG are two rubbers one bearing against one side of the commutator cylinder
and the other against the opposite side and one rubber connected to one terminal
of the machine and the other to the other terminal. Both rubbers are as shewn
in Figure 39 carried by an adjustable slide which can be moved around the axis of
the machine and locked so that the rubbers may readily be set to the position
required.
The way in which the several coils of the armature are coupled to the bars of
the commutator is illustrated in Figure 42. In this figure C is the ordinary
cylindrical core of the armature made up from coils of iron wire. C* are the coils
of insulated wire by which the core is embraced. One end of each coil is connected
as shown to one of the commutator bars G-the other end of this coil is connected
to one end of a diametrically opposite coil C+ the other end of this second coil
being coupled to a bar of the commutator G diametrically opposite to the
commutator bar to which the first mentioned coil O+ is connected.
Having thus described the nature of our invention and the manner of performing
the same we would have it understood that we claim
First. The employment of a coating of enamel around the sides of the magnet
cores or around the sides of these cores and the inner face of the frame of dynamo
electric machines to ensure perfect insulation.
Second. Insulating the conducting strips of the magnets of dynamo electric
machines from one another and from the magnet cores by the means substantially
as herein before described with reference to Figures 1 to 6.
Third. The construction of the insulated conductors of the armaturo of dynamo
electric machines substantially as herein before described with reference to
Figures 7, 15, 17, 19, 20, 21 and 22.
Fourth. The construction of the armatures of dynamo machines substantially
as herein beforo described with reference to Figures 8 to 13.
Fifth. The construction of the armatures of dynamo machines substantially as
herein before described with reference to Figures 15 to 22.
Sixth. The means substantially as herein before described with reference to
Figures 23 and 24 for allowing of the driving belt used for driving a dynamo
electric machine being readily tightened whenever required.
Seventh. The means substantially as herein before described with referenco to
Figures 14 and 25 to 32 for carrying off a current from contact rings on the axle
of dynamo electric machines.

page_text: Eighth. The construction of a continuous current dynamo electric machine
substantially as herein before described with reference to Figures 33 to 38.
Ninth. The construction of a continuous current dynamo electric machine
substantially as herein before described with reference to Figures 39 to 42.
In witness whereof I the said Sebastian Ziani de Ferranti have hereunto set
my hand and seal this Twenty fifth day of January in the year of our Lord One
thousand eight hundred and eighty four.

page_text: FIG. 5.