IMPROVEMENTS IN THE CONSTRUCTION OF ARMATURES FOR DYNAMO ELECTRIC MACHINES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
Wo ROBERT PERCY SELLON of Lambeth in the County of Surrey, Electrical
Engineer and JOHN SCUDAMORE SELLON of Hatton Garden London, Gentleman,
do hereby declare the nature of said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF ARMATURES FOR DYNAMO ELECTRIC MACHINES " to be as
follows:
This Invention relates to improvements in the construction of armatures for
Dynamo Electric machines more especially to the armatures of the disc type.
According to my Invention I form the armature core of soft band or hoop iron
which is wound upon a suitable ring or support preferably of wrought iron which
I call the "foundation ring" as it forms a substantial foundation for the first layer
of the band iron. The band iron may be wound on to the foundation ring either
in a single spiral or one or more spirals and these may be either of one or varying
widths. This spiral or these spirals are preferably in one length but may be made
in several lengths. I sometimes wind or place thin canvas, paper or some suitable
insulating and preferably incompressible substance between each layer of the band
iron. This insulating material serves to keep apart the layers of band iron and in
order to ventilate the ring thoroughly I prefer to use the insulating material of a
less width than the band iron itself; this permits of the air obtaining access to the
spaces between each layer of the band iron to facilitate the carrying off of the heat
generated.
After the band iron has been wound up to the desired depth of ring upon the
foundation ring I sometimes employ rivets passing readily through the band iron
core and foundation ring to secure them together but I may fasten the band to its
armature in any other suitable way for example by a band or tyre fixed or shrunk
on the outside of the coil. I may interpose insulating material between the rivets
and the iron of the core.
For the larger sizes of machines I may employ two or more such spirals wound
preferably on a common foundation ring and I may arrange an air space between
the several spirals and the circulation of air in this space may be' augmented by

page_text: means of holes through the foundation ring at suitable places through which air
may be drawn into the air space before mentioned and escape at the periphery
where uncovered by the wire bobbins,
In order to mount the armature upon the shaft I prefer to employ a hub con-
structed in halves or split in the plane of its rotation and each half provided with
a jaw at the outer end of each spoke that slides into a slot cut in the foundation
ring. The two halves comprising the hub are then bolted or forced together and
thus while providing a secure means of driving the ring in the direction of rotation
prevent any lateral play of the armature upon its hub.

page_text: COMPLETE SPECIFICATION,
I, ROBERT PERCY SELLON of Lambeth in the County of Surrey Electrical
Engineer and JOHN SCUDAMORE SELLON of Hatton Garden, London, Gentleman
do hereby declare the nature of our invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF ARMATURES FOR DYNAMO ELECTRIC MACHINES 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 "Improvements in the construction of armatures for
dynamo electric machines" more especially to armatures of the disc type.
According to our Invention we form the armature core of soft band or hoop
iron which is wound upon a suitable ring or support preferably of wrought iron
which I call the "foundation" ring as it forms a substantial foundation for the first
layer of the band iron. The band iron may be wound on to the foundation ring
either in a single spiral or one or more spirals and these may be either of one or of
different widths. The said spiral may be composed of a single or in some cases
of several lengths of band or hoop iron Between each layer of the band iron we
generally wind a suitable insulating substance such as thin canvas or paper which
serves to keep apart the layers of band iron and in order to ventilate the ring
thoroughly I use the insulating material of a less width than the band iron itself
This permits of air obtaining access to the spaces between each layer of the band
iron to facilitate the carrying off of any heat that may be generated.
After the band iron has been wound up to the desired depth upon the foundation
ring I fasten the last layer of the band iron to the ring by means of screws or rivets
which pass partially or completely through the spiral or spirals and the ring and
thus serve to hold the whole together and these rivets may advantageously be
insulated from the various layers of band iron by the interposition of insulating
material around the rivet To hold down the. last layer or layers of band iron we
have also found a band or tyre shrunk over the whole ring very suitable.
We also advantageously employ two or more such spirals wound preferably on a
common foundation ring and we leave an air space or spaces between the several
spirals by means of which heat generated in the ring may be carried off The
circulation of air in this space may be further augmented by means of holes drilled
through the foundation ring in such a manner that air may be drawn into the air
space or spaces before mentioned and escape at the periphery where uncovered by
the wire bobbins.
In order to mount this armature upon the shaft we prefer to employ a hub
constructed in halves, or split in the plane of its rotation each half being provided
with a jaw at the outer end of each spoke this jaw sliding into a slot cut in the
foundation ring-The two halves of the hub are then fastened together and con-
stitute a secure means through which to drivo the armature while preventing any
lateral play of the armature upon its hub The accompanying drawings serve to
illustrate clearly the manner in which the invention may be performed.
Figures 1 and 2 illustrate in side view and transverso section respectively the
armature core complete, and mounted on the hub.

page_text: a shews the hoop or band iron, the first layer of which is connected to the
foundation ring, g. The band iron is then wound up to the required depth,
insulating material c such as paper or canvas or other suitable insulation being
interposed between the convolutions of the band iron: Metallic or other rivets f
are then passed through the band iron and foundation ring and the core is then
complete: h h h indicate a few of the copper coils wound upon the armature core.
Figure 3. illustrates an armature core composed of two independent spirals or
coilings of band iron mounted on one and the same foundation ring g: the air
space at i between the spirals or coilings assists in carrying off any heat generated:
In this figure the insulation of rivets ff from the band iron coils is also shewn.
The method of mounting the armature core upon the ring is clearly shewn at
Figure 2. The foundation ring g is recessed at the inner periphery or sides or
both sufficiently to allow of the jaws b. b. of the hub (which is divided into two
parts X and Y as hereinbefore described) entering the recesses of the said ring:
The two parts of the hub are then clamped together firmly by the bolts, j. j. thus
affording a substantial means of connecting the armature to the shaft through
which the driving is effected and at the same time preventing lateral motion.
Having now particularly described and ascertained the nature of our said