Improvements in Electric Motors,
Year: 1894

page_text: Date of Application, 16th May, 1894
Complete Specification Left, 18th Mar., 1895-Accepted, 27th Apr., 1895
Improvements in Electric Motors,
I, WILLIAM MORRIS MORDEY, of 49 Queen Victoria Street, in the City of
London, Electrician, do hereby declare the nature of this invention to be as
follows
This invention has for its object improvements in-machines especially adapted for
use as motors on alternate current circuits. In constructing such machines
according to this invention, I provide both the armature and field with a number
of magnetic poles arranged in alternate order, and I arrange by means of a
commutator and one or more brushes, to short circuit the coils of the armature or of
the field during a portion of each phase.
I, WILLIAM MORRIS MORDEY, of 49 Queen Victoria Street, in the City of
London, Electrician, 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 :-
This invention has for its object improvements in machines especially adapted
for use as motors on alternate current circuits. In constructing such a machine
according to this invention, I make both armature and field with a number of
magnetic poles in alternate order, and I arrange by means of a commutator and one
or more brushes to short circuit the coils of the armature or of the field during a
portion of each phase.
In the accompanying drawings,
Figs. 1 and 2 are diagrams showing an electric motor constructed according to
this invention.
In Fig. 1, S is the field or stationary part and R the armature or rotating part.
S is wound with a
The former may be called the stator and the latter the rotor.
winding W arranged to produce poles of alternate N. and S. polarity as shewn. Ris
wound with a winding W similar in arrangement. The ends of the winding W
are connected respectively to two metal rings A and B which are connected to a
four part commutator, having sectors 1, 2, 3 and 4 in such a way that one of the
rings is joined electrically to sectors 2 and 4, whilst the other ring is joined to
sectors 1 and 3. The number of commutator sectors must be the same as the
number of poles in the armature or field. Any convenient number may be used..
Brushes are arranged to bear on the rings and on the commutator as shown
in Fig. 2. To prevent confusion, these brushes are not shown in Fig. 1. One of
bese brushes viz. a rests on the ring A, a second brush b rests on the commutator,

page_text: and a third brush crests on the ring B. Brushes a and b are joined by a wire, or
they may
form one brush; they are connected to T one of the main terminals.
Brush c is connected to the winding W and so to T' the other main terminal. By
the construction described the coils of the armature will he short circuited during a
portion of each phase.
By this means I am enabled to make a self starting alternate current motor
which runs with very little sparking.
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 1
claim is :-
An alternate current electric motor comprising a fixed field or stator having a
number of poles arranged in order of alternate polarity, an armature or rotor
having a similar number of poles also arranged in order of alternate polarity
together with a commutator, and contact rings and brushes for making and varying
the connections substantially as hereinbefore described with reference to and shown
in the drawings annexed.
Dated this 18th day of March 1895.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.