Year: 1887

page_text: Date of Application, 14th Apr., 1887
Complete Left, 22nd Sept., 1887
Complete Accepted, 4th Nov., 1887
We, WILLIAM HARDING SCOTT, and EDOUARD ALEXANDRE PARIS, both of Gothic
Works, King Street, City of Norwich, in the County of Norfolk, Electrical Engineers,
do hereby declare the nature of this invention to be as follows:-
Our invention relates to certain improvements in the armatures of dynamo electric
machines of any class in which teeth or projections are formed or attached to the core
of the armature and intended to reduce the resistance of the magnetic circuit, and it
is designed to obviate the tendency to heating of the edges of the pole pieces, and
further to obviate the tendency to the creation of Foucault or eddy currents.
In order to effect this we form teeth or projections radially to the core of the
armature of considerable depth and close together, and thus are enabled to wind the
conductor to a considerable depth upon a solid core of comparatively small diameter,
thus reducing. the relative. bulk and magnetic resistance and tendency to eddy
currents. These teeth or projections are preferably insulated from the armature core.
Dth is Ammi 1007
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Dynamo Electric Machines.
We, WILLIAM HARDING SCOTT, and EDOUARD ALEXANDRE PARIS, both of Gothic
Works, King Street, City of Norwich, in the County of Norfolk, Electrical Engineers,
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:
Our invention relates to certain improvements in the armatures of dynamo electric
machines of any class in which teeth or projections are formed or attached to the core
of the armature and intended to reduce the resistance of the magnetic circuit; and it
is designed to obviate the tendency to heating of the pole pieces, and the tendency to
the creation of Foucault or eddy currents.
In order to effect this, we form teeth or projections radially to the core of the armature
of considerable depth and close together, and thus are enabled to wind the conductor
to a considerable depth upon a solid core of comparatively small diameter, thus
reducing the relative bulk and magnetic resistance and tendency to eddy currents.
These teeth or projections are preferably insulated from the armature core.
In order that our invention may be the better understood, we now proceed to
describe the same in relation to the drawings hereunto annexed, reference being had
to the letters and figures marked thereon. Like letters refer to like parts throughout
the figures.
Figure 1 represents a section of an armature of the Paccinotti type.
Figure 2 being a transverse section of the same.
Figure 3 represents an armature of the Weston type, or such as is patented to us
under No. 4683 of 1884.
Figure 4 being a section of same.
For convenience of manufacture we prefer to make the iron core A plain and round
outside and to form the teeth of longitudinal strips of iron which are placed on edge
on the iron core. Although we have only shown for convenience of description two
types of armature, yet our improvement is applicable to almost any form. The iron
cores A may be either plates or wire, and we have at each end a strong collar of
vulcanised fibre E, or other suitable material. This collar may be fixed to a metallic
disc F, which is keyed on to the shaft G of the machine, and in the periphery of the
collar a large number of saw cuts are made, and into these saw cuts are driven
tightly the pieces of suitable insulating material B, which then form a ring of teeth
at each end of the armature. In large machines, one or more somewhat similar rings
of teeth may be made towards the middle of the periphery of the armature, the teeth
being fixed in a collar of non-metallic material, and this fixed to a metallic disc
which is keyed on the shaft. These teeth should be about the same thickness as the
iron projections, so that when the wire is wound on, or partly wound on, the iron
strips C, which form the projections, can be put into position. We prefer to make
each projection of several iron strips, as shown by the lines in the drawings, both for

page_text: the purpose of doing away with eddy currents, and for convenience of manufacture.
The strips, well insulated, are first inserted in the space between the wires, and the
rest are put in between them, the last one being driven in tight, so as to make the
whole a strong solid mass. Shallow spaces D may be cut out in the outside of
the strips which form the projections for the purpose of receiving binding wire, so
that the clearance left between the outsides of the projections and the pole piece may
not have to be increased by the thickness of the said binding wire.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
In dynamo electric machines the construction of armature in which the conductor
is wound between teeth or projections of great depth and in close proximity,
substantially as and for the purposes specified.
Dated this 30th day of June 1887.
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicants.