IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1880

page_text: LETTERS PATENT to Edwin Powley Alexander, of 14, Southampton Buildings,
in the County of Middlesex, Consulting Engineer, and British and Foreign
Patent Agent, for an Invention of "IMPROVEMENTS IN DYNAMO-ELECTRIC
MACHINES." A communication from abroad by Karl Zipernowsky, of Buda-
Pest, in the Austrian Empire.
PROVISIONAL SPECIFICATION left by the said Edwin Powley, Alexander
at the Office of the Commissioners of Patents on the 17th April 1880.
EDWIN POWLEY ALEXANDER, of 14, Southampton Buildings, in the County
of Middlesex, Consulting Engineer, and British and Foreign Patent Agent.
IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES." A communication from abroad
by Karl Zipernowsky, of Buda-Pest, in the Austrian Empire.
This Invention. relates to a construction of dynamo-electric machines, whereby
they are rendered capable of producing electrical currents of great tension suitable
for maintaining a number of lights in one circuit, or for maintaining lights or
producing mechanical power at considerable distances. For this purpose a
cylindrical armature wound lengthwise with coils of insulated wiro is caused to
revolve within a ring shaped electro magnet, which consists of an iron ring wound
over sections of its circumference with coils of insulated wire so as to produce a
number of successive polar fields of alternating polarity. The armature revolving
within this ring has currents induced in its coils, these currents being alternated
in each coil as it passes the successive polar fields of the surrounding electro
magnet, and the number of alternations being thus multiplied without having
recourse to great speed of rotation. The currents are collected in the usual way by
a cylindrical commutator, some of them being used to excite the electro-magnets of
the machine, and others being carried through external circuits. When very strong
currents have to be produced during short periods, the core of the armature is made
of wrought iron plates of which the continuity is interrupted. For producing
continuous uniform currents the core is made of spiral shaped rings of wrought

page_text: iron insulated wire wound round a cylinder of wood or non-magnetic material.
The coils of the armature are wound in the form of rectangles, having their long
sides parallel to the axis, the width of each coil being such that its two sides are
at the same time approaching and leaving two of the fields of opposite polarity of
the electro magnet, so that currents of like direction and force are at the same
time induced in both sides of cach coil. In order to diminish wear of the
commutator plates and keep their surfaces clean they are lubricated by pure
petroleum. For this purpose a vessel containing the petroleum is fixed above the
commutator with a porous wick extending down from it so as to bear tangentially
against the cylindrical surface of the commutator. The armature is made hollow
with openings through its ends and its periphery so that currents of air may pass
through it to keep the machine cool.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edwin Powley Alexander in the Great Seal Patent Office on the
16th October 1880.
EDWIN POWLEY ALEXANDER, of 14, Southampton Buildings, in the County
of Middlesex, Consulting Engineer, and British and Foreign Patent Agent.
IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES." A communication from abroad
by Karl Zipernowsky, of Buda-Pest, in the Austrian Empire.
16
The said Invention relates to a construction of dynamo-electric machines,
whereby they are rendered capable of producing electrical currents of great tension
suitable for maintaining a number of lights in one circuit, or for maintaining lights
or producing mechanical power at considerable distances. For this purpose a
cylindrical armature wound lengthwise with coils of insulated wire is caused to
revolve within a ring shaped electro-magnet, which consists of an iron ring wound
over sections of its circumference with coils of insulated wire, so as to produce a
number of successive polar fields of alternating polarity. The armature revolving
within this ring has currents induced in its coils, these currents being alternated in
each coil as it passes the successive polar fields of the surrounding electro-magnet,
and the number of alternations being thus multiplied without having recourse to
great speed of rotation. The currents are collected in the usual way by a cylindrical
commutator, some of them being used to excite the electro magnets of the machine,
and others being carried through external circuits. When very strong currents
have to be produced during short periods the core of the armature is made of
wrought iron plates of which the continuity is interrupted. For producing
continuous uniform currents the core is made of spiral shaped rings of wrought
iron insulated wire wound round a cylinder of wood or non-magnetic material.
The coils of the armature are wound in the form of rectangles, having their long
sides parallel to the axis, the width of each coil being such that its two sides are
at the same time approaching and leaving two of the fields of opposite polarity of
the electro-magnet, so that currents of like direction and force are at the same
time induced in both sides of each coil. In order to diminish wear of the
commutator plates and keep their surfaces clean they are lubricated by pure
petroleum. For this purpose a vessel containing the petroleum is fixed above the
commutator with a porous wick extending down from it so as to bear tangentially
against the cylindrical surface of the commutator. The armature is made hollow
with openings through its ends and its periphery so that currents of air may pass
through it to keep the machine cool.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall
refer to the several explanatory Figures on the annexed Sheet of Drawings.
Figure 1 of the Drawings represents a half end elevation and half transverse
section of the said improved dynamo-electric machine; Figure 2 is a longitudinal
vertical section of the same. The apparatus consists of a cylindrical armature
wound longitudinally with insulated wire and carried in bearings in the framing BB,
and rotated between the ring shaped magnets N N, SS, N'N', S'S'. By means of
the driving pulley C there are provided polar extensions projecting inwards, and so
arranged that those of opposite polarity follow each other.
By the rotation of the armature the currents produced in the same will change
their direction 4 or 6 or 8 times during one revolution, according to the number of
polar extensions, or generally if their number be 2n, where n represents any
number, there will be 2n changes of direction, which currents may form n separate
circuits, of which, however, several may be combined to form one circuit.
Of the currents so produced one or more are employed for exciting the electro

page_text: magnets, in order to be utilized as dynamo-electric currents while others form
separate circuits as magneto-electric currents.
If the number of polar extension's be n, and N be a number determined
according to the diameter of the induction wire employed, the number of separate
coils of copper wire which form the induction wire will be equal to N × n × n =
Nn³.
By winding on the wire coils of the armature in rectangles, of which the two
long sides are always approaching or receding from polar fields of opposite polarity,
as before described, the portions of the coils situated at the smaller sides of the
rectangle will also be effective by reason of the inductive action of the iron core,
so that the whole of the wire coil is rendered available.
Figure 3 shows the before described arrangement for lubricating the surface of
the commutator for diminishing wear of the rubbing surfaces, and for keeping
them free from oxidation. It consists of a vessel D filled with puro petroleum,
and having a capillary wick extending down from it, and pressed against the surfaco
of the commutator by a spring E attached to the vessel.
The commutator has as many contact plates or brushes as there are polar
extensions to the electro-magnets.
Figure 4 shows a cross section through the hollow armature, which as heroin-
before stated has openings at its ends A, A, (Figures 1 and 2) and its periphery, and
has internal oblique vanes F, F, which as the armature rotates will produce currents
of air through the armature so as to cool it.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein before in part
recited Letters Patent is,-
First. The herein described construction of dynamo-electric machines wherein
currents of the same direction are produced.
Second. The herein described peculiar construction of the electro-magnets in the
form of rings with inwardly projecting polar extensions.
Third. The herein described peculiar mode of coiling the wire on the armature for
producing currents both of uniform and of alternating direction.
Fourth. The herein described arrangement for ventilating the armature of the
machine.
Fifth. The herein described method of lubricating the surface of the commutator.
Sixth. The use of the herein described dynamo-electric machine for the production
of motive power.
In witness whereof, I, the said Edwin Powley Alexander, have hereunto
set any hand and seal, this Fourteenth day of October, in the year of our
Lord One thousand eight hundred and eighty.