Year: 1887

page_text: Date of Application, 15th Jan., 1887
Complete Left, 17th Oct., 1887
Complete Accepted, 14th Jan., 1888
1, SEBASTIAN ZIANI DE FERRANTI of 5 Stanwick Road, West Kensington, in the
County of Middlesex, Electrician, do hereby declare the nature of this invention to
be as follows:-
My improvements relate more especially to dynamo electrical machines such as are
described in the Specification of a patent No. 3702 in the year 1883.
The revolving armature I mount on the end of an axis which has a driving pulley
fixed upon it by which it can be driven. This pulley is placed between the bearings in
which the axis is carried. The fixed magnets which are on each side of the
armature I divide into four sections two on one side and two on the other-and I
make them capable of each being readily slidden away the one from the other so that
both they and the revolving armature can readily be got at for cleaning.
The armature as before I make of a number of coils ranged around the circum-
ference of a disc or wheel but in place of making each coil from a flat strip of metal
I make it from a strip of metal which is dished or hollowed in cross-section so that
the outer coils overlap or embrace the inner ones or are otherwise corrugated or ribbed
so that the overlying coils interlock one with another. In this way the overlying coils
are not only kept from shifting sidewise but in addition a much stronger coil is obtained
which will retain the form in which it is originally coiled and which will not elongate or
spread outwards away from the centre of the wheel or disc when this wheel or disc is
rapidly rotated. The ends of the coils which are next to the periphery of the disc or wheel
are received into semicircular recesses in metallic blocks. Each of these blocks is on one
side or it might be on both sides formed with a finger or projection which extends
outwards from it radially and lies along the side of the coil between it and the
next coil and serves to carry round the coil with the wheel when the wheel is
revolved.
To hold the coil into the semicircular recess and prevent its flying outwards from
it in place of using a circular pin as described in the Specification herein before
mentioned I use a piece of metal somewhat of a U shape which not only fits to the
inner bend of the coil but also to its diverging sides for some distance outwards.

page_text: Each of these U shaped pieces is formed in one piece with two plates one on either side
of it. These extend inwards towards the centre of the wheel and come on either side
of the blocks that the inner bends of the coils rest against.
The plates extend inwards beyond the blocks and between them a filling piece is
inserted insulating material being placed between the filling piece and the block. The
Ushaped piece and the filling blocks are pressel forcibly one towards another so that
the inner ends of the coils are firmly gripped-rivets are then placed through the
plates and filling blocks so as to hold all firmly together. The plates at their inner
ends have flanges extending outwards from them and by these they are held to the
circumference of the wheel. They rest against insulating material interposed between
them and the outer circumference of the rim of the wheel.
Clamping rings divided radially into segments (preferably one for each coil) are
placed at the sides of the rim of the wheel. They each overlap part of its inner
circumference and also the flange which extends outwards from one of the plates
above mentioned. The clamp on one side is drawn towards the clamp on the other
side by a bolt passing through the periphery. Over the flanges of the plates and
against their ends are placed flat pieces of insulating material and outside these are
placed metallic segments which on their outer sides are coned to fit the coned surface
of the holding down segments. In place of the plates being formed with flanges
extending sidewise from them and held to the rim of the wheel by these flanges, the
plates might be formed in one piece with a block of a dovetail or such like form to
enter corresponding grooves cut crosswise of the rim of the wheel.
All the parts are in this manner held securely to the rim of the wheel when the
clamps on either side of it are drawn one towards another.
The filling blocks are coupled by metallic bolts between them. The plates are also
similarly coupled. At one
or it might be more points of the circumference
current is led off by rods and bolts from the onds of two adjacent coils one to
a contact disc at one end of the hub or centre of the wheel and the other to an
insulated ring at the other end and from them the current is carried away by
rubbers.
In this way the conductors of the coils may be coupled in series or parallel or in a
combination of both according to the way in which the connecting studs are
put in.
Dated this 15th day of January 1887
CARPMAEL & Co.,
Agents for the Applicant.

page_text: Improvements in Dynamo Electrical Machines.
I, SEBASTIAN ZIANI DE FERRANTI of 5 Stanwick Road, West Kensington, in the
County of Middlesex, Electrician, 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 :-
1
My improvements relate more especially to dynamo electrical machines such as are
described in the Specification of a Patent No. 3702 in the year-1883.
The revolving armature I mount on the end of an axis which has a driving pulley
fixed upon it by which it can be driven. This pulley is placed between the bearings in
which the axis is carried. The fixed magnets which are on each side of the armature
I divido into four sections two on one side and two on the other and 1 make them
capable of each being readily slidden away the one from the other so that both they
and the revolving armature can readily be got at for cleaning.
The armature as before I make of a number of coils ranged around the circum-
ference of a disc or wheel but in place of making each coil from a flat strip of metal
I make it from a strip of metal which is dished or hollowed in cross section so that
the outer coils overlap or embrace the inner ones or are otherwise corrugated or
ribbed so that the overlying coils interlock one with another. In this way the
overlying coils are not only kept from shifting sidewise but in addition a much
stronger coil is obtained which will retain the form in which it is originally coiled and
which will not elongate or spread outwards away from the centre of the wheel or disc
when this wheel or disc is rapidly rotated.
In the Specification of the patent above mentioned I described the so making the
armature that each individual coil in addition to its own insulation was also insulated
from the wheel or central portion of the armature by insulating material at a
considerable distance from the magnetic field.
Armatures of this construction can readily be made capable of furnishing currents
of very high intensity as the insulating material interposed at the point where the
coils are connected to the wheel being at a distance from the magnetic field can
readily be made of any thickness and of any insulating capacity so as to be capable of
resisting the cumulative electro motive force of all the bobbins whilst the insulation
in each bobbin itself need only be sufficient for the electro motive force in that
bobbin.
I now construct such an armature in the following manner :-
The ends of the coils which are next. to the periphery of the disc or wheel I cause
to be received into semicircular recesses in metallic blocks. Each of these blocks
may be on one or both sides formed with a finger or projection which extends
outwards from it radially and lies along the side of the coil between it and the
next coil and serves to carry round the coil with the wheel when the wheel is
revolved.
To hold the coil into the semicircular recess and prevent its flying outwards from it

page_text: in place of using a circular pin as described in the Specification herein before mentioned
. I use a piece of metal somewhat of a U shape which not only fits to the inner bend of
the coil but also to its diverging sides for some distance outwards. Each of these
Ushaped pieces is formed in one piece with two plates one on either side of it. These
extend inwards towards the centre of the wheel and come on either side of the blocks
that the inner bends of the coils rest against.
The plates extend inwards beyond the blocks and between them a filling picce is
inserted insulating material being placed between the filling piece and the block. The
Ushaped piece and the filling piece are pressed forcibly ono towards another so that
the inner ends of the coils are firmly gripped-rivets are then placed through the
plates and filling piece so as to hold all firmly together. The plates at their inner
ends have flanges extending outwards from them and by these they are held to the
circumference of the wheel. They rest against insulating material interposed between
them and the outer circumference of the rim of the wheel.
Clamping rings divided radially into segments (preferably one for each coil) are
placed at the sides of the rim of the wheel. They each overlap part of its inner
circumference and also tho flange which extends outwards from one of the plates
above mentioned. The clamp on one side is drawn towards the clamp on the other
side by a bolt passing through the periphery. Over the flanges of the plates and
against their ends are placed flat pieces of insulating material and outside these are
placed metallic segments which on their outer sides are coned to fit the coned surface
of the holding down segments. In place of the plates being formed with flanges
extending sidowise from them and held to the rim of the wheel by these flanges, the
plates might be formed in one piece with a block of a dovetail or such like form to
enter corresponding grooves cut crosswise of the rim of the wheel.
All the parts are in this manner held securely to the rim of the wheel when the
clamps on either side of it are drawn one towards another.
The filling pieces are coupled by metallic bolts between them. The plates are also
similarly coupled. At one or it might be more points of the circumference current is led
off by rods and bolts from the ends of two adjacent coils-one to a contact disc at one
end of the hub or centre of the wheel and the other to an insulated ring at the other
end and from them the current is carried away by rubbers.
In this way the conductors of the coils may be coupled in series or parallel or
in a combination of both according to the way in which the connecting studs are
put in.
The drawings annexed shew the above improvements-Figure 1 is a longitudinal
section, Figure 2 a side elevation of a dynamo electrical machine formed in the
manner described to allow of the revolving armaturo being readily got at for cleaning
or repairs. Figure 3 is a side elevation partly in section of the machine when the
sections carrying the fixed magnets have been moved away from one another to give
free access to the armature.
A is the revolving armature mounted on the end of its axis B. C is the driving
pulley fixed on the axis between the bearings in which the axis B is mounted. D are
the fixed magnets-the frame that carries them is in four sections held together by
bolts. When these are withdrawn any one or all of the sections can be removed so
that both the fixed magnets and armature can be readily got at..
It will be obvious that in place of an armature being carried at one end only of
the axis a double dynamo might be made with an armature carried at each end of the
axis.
Figure 4 is a side elevation with parts removed of part of the armature constructed
as described in such a manner as to allow of insulating material of any thickness being
interposed between the wheel of the armature and the parts which hold the armature
coils to it.
Figure 5 is a transverse section through part of the periphery of the wheel and one
of the coils.
EE aro the coils. F F are blocks each formed with a semicircular recess to receive
the inner end of one of the coils-F' is a finger extending outwards from each block

page_text: to come between adjacent coils-a similar finger might be on each side of the block or
the block might be formed without any finger extending from it. G is the U shaped
block by which each coil is to be held to the wheel.. It is formed with two plates G¹
one on either side of it extending inwards towards the centre of the wheel and
beyond the block F. His a filling piece inserted between the two plates G' where
they extend beyond the block F. Insulating material is as shown by a black line in
Figures 4 and 5 placed around the block F, and coil E, to insulate them from the
block G and filling piece H.
As above mentioned the pieces G and filling pieces H are pressed forcibly together
and rivets I are then passed through the plates G' and filling piece to hold all firmly
together.
G² are flanges extending outwards from the inner ends of the plates G-by these
the piece G and coil carried by it is secured to the circumference of the wheel J which
forms the central portion of the armature. K is insulating material placed at the
sides of the plates G¹ and above and below and at the ends of the flanges G to insulate
them from the wheel. L are inetallic clamping segments by which the pieces G are
held to the circumference of the wheel-they are placed on the two sides of the wheel
and are drawn together by bolts M which pass through the tyre or outer circumference
of the wheel as shewn in Figure 5. N are metallic segments interposed between the
clamps L and the insulating material to prevent injury to the insulating material as
the nuts on the bolts M are tightened up.
As the insulating material K is situated at a distance from the magnetic field it is
practicable to make it of considerable thickness and of materials possessing high
insulating capacity such for example as sulphur and consequently it renders it
practicable to construct machines to produce currents of very high intensity.
In place of forming the pieces G with flanges G extending outwardly from the
inner ends of tho plates G as shown at Figure 6 and in Figures 4 and 5 they might
be formed with T headed projections to be received in corresponding recessos in the
circumference of the wheel as shown at Figure 7-thick insulation being placed
between the two. Or other like means may be adopted for securing the clamps
within which each coil is independently clamped and held to the wheel and providing
for the interposition of a thick layer of insulating material between the clamp and the
wheel.
The blocks F of the several clamps are shown to be electrically coupled in pairs by
pins O and the plates G₁ to be similarly coupled in pairs by plates P.
At one or more points current is led off by rods from the ends of adjacent coils to
contact discs on the armaturo axis. -
Figures 8, 9, 10 and 11 shew cross sections of examples of strips of metal I use for
forming the armature coils. The form in cross section may be varied so long as it is
of such a form that the overlying coils interlock one with another.
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. A dynamo electrical machine in which the armature is mounted on the end
of an axis supported in a pair of bearings between which it has a driving pulley fixed
upon it and in which the fixed magnets are divided into four sections which can be
slidden away the one from the other substantially as described.
2. In multiple magnet dynamos that is in dynamos in which more than two magnet
poles are used mounting the armature on the armature axis outside the bearings in
which the axis is carried.
3. Securing the coils of the armature each in a separate clamp and subsequently
securing such clamp to the rim of the armature wheel with thick insulating material
interposed between them substantially as described:
4. Holding the armature coils in clamps each composed of a piece fitting to the
interior of the sides and inner end of the coil and having projecting plates between
which is held by rivets or other secure fastenings a block that fits to the exterior

page_text: of the inner end of the coil and which projecting plates are formed with feet or
flanges to facilitate their attachment to the circumference of the wheel substantially as
described.
5. Forming the armature coils from strips of metal corrugated dished or hollowed
in cross section substantially as described.
6. In double dynamos carrying the two armatures at the two ends of a shaft
supported in two bearings and placing the driving pulley in the centre between the
two bearings.