Improvements in the Armatures of Dynamo Machines.
Year: 1889

page_text: Date of Application, 3rd June, 1889
Complete Specification Left, 1st Mar., 1890-Accepted, 5th Apr., 1890
PROVISIONAL SPECIFICATION
Improvements in the Armatures of Dynamo Machines.
I, CHARLES EUGENE LANCELOT BROWN, of The Maschinenfabrik, Oerlikon near
Zurich, Switzerland, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
The armatures of dynamos of the drum or Siemens type have not hitherto been used
for machines which give a high difference of potential because from the nature of the
winding the full difference of potential of the machine exists between wires which are
wound side by side and the secure insulation of these wires from one another is
difficult.
Now by my new method of construction I am able to make armatures of the drum
or Siemens type for high tension which are quite as safe as Gramme armatures. The
method of construction I employ is a modification of the Siemens winding. Calling
the successive wires around a norinally wound armature, having one layer of
wire 1, 2, 3, 4, 5, 6 &c., in an' armature constructed according to my improved
method, with the conductors built up or formed, instead of being wound, the wires
numbered 1, 3, 5, 7, &c. occupy one layer and fill up the whole circumference, and
those numbered 2, 4, 6, 8, &c., occupy another layer above and separated from the
former by a sheet of insulating material of sufficient thickness to safely withstand the
full volts of the machine. By this means the insulation of the wires, between which
there is a great difference of potential, cannot become bridged over by dust or
metallic particles, and thereby rendered unsafe, as is the case if the same wires are
arranged side by side and separated only by their covering or by a strip of insulating
material in addition.
1000
C. E. BROWN,
Per F. J. B.
COMPLETE SPECIFICATION.
Improvements in the Armatures of Dynamo Machines.
1, CHARLES EUGENE LANCELOT BROWN, of The Maschinenfabrik, Oerlikon near
Zurich, Switzerland, Electrical Engineer, 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 :-
The armatures of dynamos of the drum or Siemens type have not hitherto been
used for machines which give a high tension because from the nature of the winding
the full difference of potential of the machine exists between wires which are wound
side by side and the secure insulation of these wires from one another is difficult.
Now by my new method of construction I am able to make armatures of the drum
or Siemens type for high tension which are quite as safe as Gramme armatures. The
method of construction 1 employ is a modification of the Siemens winding. Calling
the successive wires or coils of wire (hereinafter referred to as wires) around a
normally wound armature, having one layer of wire, 1, 2, 3, 4, 5, 6, &c., in an
armature constructed according to my improved method, with the conductors built up
or formed, instead of being wound, the wires numbered 1, 3, 5, 7, &c., occupy one
layer and fill up the whole circumference, and those numbered 2, 4, 6, 8, &c., occupy
another layer above and are completely separated from the former for the whole of
their length by a continuous sheet of insulating material of sufficient thickness to
safely withstand the full volts of the machine. By "continuous" is meant in all

page_text: cases continuous as far as regards its insulating properties. Mechanically it may be
sheets of insulating material sewed together or wound on helically or otherwise at
convenience. By this means the insulation of the wires, between which there is a
great difference of potential, cannot become bridged over by dust or metallic particles,
and thereby rendered unsafe, as is the case if the same wires are arranged side by side
and separated only by their covering, or by a strip of insulating material in addition.
In special cases where two layers cannot be employed I modify my method of
winding as follows:-I wind the first layer of wire in such a way as to leave between
two consecutive wires, a space corresponding to the size of the wire together with
twice the thickness of the required insulation. Above the first layer I place the
insulating material in a loose manner, and afterwards I lay in place the second layer
of wires, pressing them down on the insulating material in the space left between the
wires of the first layer. It will easily be seen that the whole winding of the armature
is divided into two different parts by a continuous layer of insulating material which
separates the wires between which a great difference of potential exists for the whole
of their length from one another.
Referring to the accompanying sheet of drawings,
Fig. 1 shews diagrammatically the ordinary method of drum or Siemens winding..
The wires are numbered at the periphery 1-20) consecutively. The position of the
brushes being, for example, that indicated in the drawing, a simple inspection will
shew that between the wires 6 and 7 and 16 and 17 the same difference of potential
exists as between the two brushes i.e. the maximum; while between the wires 5 and 7,
6 and 8, 15 and 17 or 16 and 18 the difference of potential corresponds to that
existing between two neighbouring sections of the collector. Whilst, then, between
two wires bearing consecutive numbers the difference of potential attains a maximum
twice in each revolution of the armature, the difference of potential between any two
neighbouring wires which bear even numbers, or two which bear odd numbers, is
never higher than that which exists between two consecutive collector bars.
Fig. 2 shews diagrammatically the method of winding according to my invention
with the wire in two separate layers.
Fig. 3 shews diagrammatically the method of winding according to my invention
when the two series of wires are wound in one layer but separated by a continuous
sheet of insulation.
The method I adopt for carrying my system of winding into execution is as
follows:-
I first cut off as many pieces of insulated wire as there are wires on the armature
bearing, for example, uneven numbers. I place these on the surface of the drum with
a short piece projecting over the collector and a long piece at the opposite end. Then
I bend all the short ends down by a suitable curve to the collector and solder them in
their respective slots, and also bend down all the long ends by a similar curve
towards the axle. I then slip a flat ring of wood or other insulating substance over
the collector and a similar ring over the axle at the further end and press both rings
up against the wire. I then cover the whole exposed surface of the wires around the
drum with paper treated with shellac or some other insulating material rolling it
tightly around the wires if I am carrying out the system shewn in Fig. 2, or wrap
loosely around the armature, insulating cloth or some other flexible insulating
material if the system adopted is that shewn in Fig. 3. I then pull the long ends
of the wires that extend through the hole in the insulating disc to the outside, and by
a suitable curve to the surface of the armature, and over the insulating wrapping (see
the wires bearing even numbers in the diagram) to their proper sections in the
commutator.
I obtain in this manner a drum wound with two layers or series of wires so disposed
that between two neighbouring wires of one and the same layer or series there exists
only a very small difference of potential, while the two layers or series are insulated
from one another as thickly as may be desired.
..
The continuity of the insulating material or layer constitutes an essential feature of

page_text: my invention for it is precisely this continuity of the insulating material that prevents
an accumulation of copper dust, grease &c., setting up communication between wires
belonging to two different parts of the winding.
It is evident that this method of winding is applicable not only to two pole
machines but to those with any number of poles and to drum winding in series
or parallel.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The construction of a drum wound armature in which the wires between which
the maximum difference of potential may exist are completely separated over the
whole armature and throughout their length by an interposed continuous sheet of
insulating material one half the wires lying at one side of the said sheet, and the other
half at the other side.
2. The improved method of winding and insulating the wires of drum armatures
substantially as described with reference respectively to and shewn in Fig. 2 and in
Fig. 3 of the drawings annexed.
1000