IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES
Year: 1882

page_text: LETTERS PATENT to Charles Ambrose McEvoy and James Mathieson both of
18 Adam Street Adelphi in the County of Middlesex for an Invention of
"IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES"
PROVISIONAL SPECIFICATION left by the said Charles Ambrose McEvoy
and James Mathieson at the Office of the Commissioners of Patents on the
27th November 1882.
"
CHARLES AMBROSE M°EVOY and JAMES MATRIESON both of 18 Adam Street
Adelphi in the County of Middlesex "IMPROVEMENTS IN DYNAMO ELECTRIC
MACHINES
This invention has for its object improvements in dynamo electric machines.
For this purpose we construct the revolving armature ring or wheel of such
machines of a central boss of gun metal or other non magnetic material to be
secured to the axis and which has spokes radiating from it which at their outer end
are forked or made U shaped-A ribbon of soft iron is wound into a ring around
the outer ends of the spokes being laid between the two prongs of their forked
ends. Numerous turns of the ribbon are thus wound one over the other until the
required depth or thickness of iron core or ring is attained
On to the ring so formed are then wound the several coils of insulated conducting
wire in the ordinary manner one by the side of the other all around the ring. The
inner end of each coil is also connected to the outer end of the next succeeding
coil and also by a radial conducting bar at one side of the ring to one or other of
a number of insulated contact bars which are ranged lengthwise of the axis in the
ordinary manner.
By forming the iron ring in the manner above described of a ribbon wound
between forks at the outer end of spokes radiating from a central boss the ring can
be readily constructed and can be centred in a very substantial manner

page_text: Any one or more of the coils of conducting wire which embrace the ring between
the spokes can also be readily unwound and removed if required without removing
the ring from its axle or disturbing any of the other coils.
The magnet poles we form so as not only to come opposite to the outer circum-
ference of the ring but also to come opposite to the two sides of the ring so as more
completely to expose the coils which it carries to the full force of the magnetic
field. For this purpose we channel out a groove in the two semi-circular cast or
wrought iron magnet poles for the armature ring with the coils it carries to enter
Preferably we make the cores of the magnets to stand out sidewise from both
sides of the magnet poles.

page_text: C
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Ambrose MoEvoy and James Mathieson in the Great Seal
Patent Office on the 26th May 1883.
CHARLES AMBROSE M°EvoŶ and JAMES MATHIESON both of 18 Adam Street
Adelphi in the County of Middlesex "IMPROVEMENTS IN DYNAMO ELECTRIC
MACHINES
"
This Invention has for its object improvements in dynamo electric machines.
For this purpose we construct the revolving armature ring or wheel of such
machines of a central boss of gun metal or other non magnetic material to be
secured to the axis and which has spokes radiating from it which at their outer
end are forked or made U shaped. A ribbon of soft iron is wound into a ring
around the outer ends of the spokes being laid between the two prongs of their
forked ends, Numerous turns of the ribbon are thus wound one over the other
until the required depth or thickness of iron core or ring is attained.
Onto the ring so formed are then wound the several coils of insulated conducting
wire in the ordinary manner one by the side of the other all around the ring. The
inner end of each coil is also connected to the outer end of the next succeeding coil
and also by a radial conducting bar at one side of the ring to one or other of a
number of insulated contact bars which are ranged lengthwise of the axis in the
ordinary manner.
By forming the iron ring in the manner above described of a ribbon wound
between forks at the outer end of spokes radiating from a central boss the ring can
be readily constructed and can be centred in a very substantial manner.
Any one or more of the coils of conducting wire which embrace the ring between
the spokes can also be readily unwound and removed if required without removing
the ring from its axle or disturbing any of the other coils.
The magnet poles we form so as not only to come opposite to the outer circum-
ference of the ring but also to come opposite to the two sides of the ring so as
more completely to expose the coils which it carries to the full force of the
magnetic field. For this purpose we channel out a groove in the two semi-circular
cast or wrought iron magnet poles for the armature ring with the coils it carries
to enter.
Preferably we make the cores of the magnets to stand out sidewise from both
sides of the magnet poles.
The above described improvements are illustrated in the drawings hereunto
annexed.
Figure 1 shows a front view of the frame of the machine and the magnets and
magnet pole pieces carried by it the pole pieces being shown in section.
Figure 2 shews a side elevation of the machine-Figure 3 shews a side elevation
of the magnet pole pieces. Figure 4 shews a side elevation of the armature ring-
and Figure 5 a section of the same.
In these figures A A is the frame B B are the magnet pole pieces shaped as
shewn at Figure 1 to come opposite to each side of the armature ring C as well as
opposite to its outer circumference. DD are soft iron cores secured to each side of
the pole pieces by bolts E which also lock these pole pieces to the frame of the
machine. The pole pieces are surrounded by insulated wire coils in the ordinary
way-The commutator brushes are carried on centres at F F.
The armature ring or wheel is shewn on a somewhat larger scale at Figures 4
and 5-G is the boss of the ring or wheel fast on the axis H-G' are spokes
radiating from the boss-G² are the outer forked ends of these spokes-H¹ H¹ is a

page_text: ribbon of soft iron wound as shown in numerous overlapping coils around the
forked outer ends of the spokes G' so as to form a ring of the dimensions required.
The ribbon is of such a width that it just lies between the two prongs of each
forked spoke. H2 H2 are some of the coils of insulated wire which have to be
placed side by side all around the ring and connected the one to the other in the
ordinary way and as above described.
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 construction of the revolving armature ring or wheel of dynamo
electric machines substantially as hereinbefore described.
Second. The construction of the magnet pole pieces of dynamo electric machines
with a groove or channel along their inner circumference so that the surface of the
pole piece may not only be in close contiguity to the outer circumference of the
revolving ring or armature but also in close contiguity to its sides substantially as
herein before described. -
L
0
In witness whereof I the said Charles Ambrose McEvoy have hereunto set
my hand and seal this Twenty sixth day of May in the year of our Lord
One thousand eight hundred and eighty three.