IMPROVEMENTS IN THE ARMATURES OF DYNAMO MACHINES
Year: 1884

page_text: I CHARLES FRIEND COOPER of Norbiton Lodge Kingston on Thames in the
County of Surrey Engineer, do hereby declare the nature of my invention for
"IMPROVEMENTS IN THE ARMATURES OF DYNAMO MACHINES" to be as follows:-
1
This Invention has for its object improvements in the armatures of dynamo
machines.
I construct the armature of a dynamo machine of a cylinder of soft iron (which
should be built up of a series of rings) and two end frames of bronze or other
non-magnetic metal with spokes and central bosses into which the axis is keyed.
The soft iron cylinder is fixed to the end frames (and so connected with.
the axis) by bolts or ties parallel to the axis passed through holes bored in
the substance or walls of the cylinder and through corresponding holes in the
circumference of the end frames.
The armature is wound with coils in which the wire passes parallel to the axis
within and without the cylinder.
Doted this 2nd do.. of T7001
CARPMAEL & Co.,
Agents for the Applicant.

page_text: e armature is wound with coils in which the wire passes parallel to the axis
Figure 1 is a side view partly in section and
Figure 2 is an end view of the armature of a dynamo electric machine
constructed in accordance with my invention.
A is the axis of the armature.
B B are end frames of bronze or other non-magnetic metal. The frames have
bosses by which they are keyed on to the axis, and radial arms connected at their
outer ends by a ring.
Between the two frames B B a series of soft iron rings C. C. are held which
rings may or may not have projections C. C. to keep the windings of insulated
wire in place but I do not consider the use of such projections as novel.
DD are bolts passing through all the rings C. C. by holes made to receive them
and also through holes in the end of the frames. The bolts are rivetted at their
ends and they secure the soft iron rings to the end frames B B and so to the
axis A. The rings C. C. have no radial arms or interior projections for keeping
the wire in place and are unconnected with the axis except by the end frames B. B.
The absence of arms and bosses to the rings allows of better distribution and
arrangement of the coils and allows of a freer circulation of air.
Figures 3 and 4 show an armature also constructed according to my invention
and differing only from that already described in that the bolts D D are clothed
with insulating material and so are electrically and magnetically insulated from the
ring C.
The advantages derived from insulating the bolts is that local and adverse
magnetic currents are rendered innocuous.
Figures 5 and 6 show an armature similar to that represented by Figures 1
and 2 except that the bolts D D in this case pass through lugs projecting from the
rings C in the direction of the axis, the section of the rings is not then reduced by

page_text: the bolt hole. The bolts also pass through the radial arms of the end frames B.
These armatures are wound in the usual manner with insulated conductor passing
to and fro in a direction parallel to the axis and within and without the rings C.
The arrangements in respect to the field magnets and the electrical arrangements
throughout are as is usual in dynamo electric machines of this type.
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
My improved armature consisting of a soft iron cylinder built up from a series
of rings or sections of rings supported and connected with the axis at its ends only
and this by means of frames of non magnetic metal as herein described.
CHARLES FRIEND COOPER.
Carpmael & Co.,
Agents for the Applicant.