Year: 1887

page_text: Date of Application, 5th May, 1887
Complete Left, 6th Feb., 1888
Complete Accepted, 9th Mar., 1888
I, JOSEPH DEVONPORT FINNEY ANDREWS of Woodside Electric Works, Glasgow
in the County of Lanark, N.B. Electrical Engineer do hereby declare the nature of
this invention to be as follows:-
Electro-motors as they are usually arranged to be worked by alternating currents,
have a number of separate polar fields and a corresponding number of armature coils,
so arranged that the armature moves one step, that is to say, each armature coil
moves from one polar field to the next, at each reversal of current and, consequently,
it is found advantageous to arrange the number of the fields and coils to correspond
with those in the machine which generates the alternating currents, in order to ensure
the necessary synchronism of action. My invention relates to a construction and
arrangement of electro motor in such a manner that its action is independent of the
alternations of the current, and of the alternate current generating machine with
which it may be connected. For this purpose I employ any known form of
dynamo machine having two or more polar fields, the cores of the magnets being
preferably of iron wire or of thin iron plate, and I connect their coils in the manner
usually adopted in the dynamo machines. The coils of the armature and commutator
plates to which they are connected are so arranged that, whether their current be in
the one direction or the other, each armature coil has for the moment polarity
opposite to that of the field pole towards which it is presented, the reversals of current
acting similarly and synchronously on both of them. Whatever, therefore, may be
'the period of these reversals produced by the generating machine, the movement of
the motor is independent of them in respect of turn.
According to a modified arrangement I construct the field magnets without iron
and in this case I arrange the coils to envelope the armature and so act upon it direct.
The armature may, with advantage toward efficiency, also be made without iron for a
core. The size and weight of motors constructed according to this modification would
be greater.
ABEL & IMRAY,
Agents for the Applicant.

page_text: I, JOSEPH DEVONPORT FINNEY ANDREWS of Woodside Electric Works, Glasgow
in the County of Lanark N.B. 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 :-
Electro motors as they are usually arranged to be worked by alternating currents
have a number of separate polar fields, and a corresponding number of armature coils
so arranged that the armature moves one step, that is to say, each armature coil
moves from one polar field to the next, at each reversal of current and consequently,
it is found advantageous to arrange the number of the fields and coils to correspond
with those in the machine which generates the alternating currents, in order to
ensure the necessary synchronism of action. My invention relates to a construction
and arrangement of electro-motor in such a manner that its action is independent of
the alternations of the current, and the alternate current generating machine with
which it may be connected. For this purpose I employ any known form of dynamo-
machine which may have several polar fields, the cores of the magnets being
preferably of iron wire, or thin iron plate, and I connect their coils in the manner
usually adopted in the dynamo machines. The coils of the armature and commutator
plates to which they are connected are so arranged and connected to the field magnet
coils that, whether the supply current be in the one direction or the other, each
armature coil has for the moment polarity opposite to that of the field pole towards
which it is presented, the reversals of current acting similarly, and synchronously on
both the armature and the field magnet coils. Whatever therefore may be the period
of the reversals of current produced by the generating machine, the movement of the
motor is independent of them in respect of time.
According to a modified arrangement I construct the field magnets without iron
and in this case I arrange the coils to envelope the armature and so act upon it direct.
The armature may with advantage toward efficiency, also be made without iron for a
core. Fig. 1 of the accompanying drawings is a diagram illustrating the connection
of the coils of a dynamo machine of known type, so as to render its action as a motor
worked by alternating currents independent in point of time of the generating
machine which supplies it with electricity. The coils of the armature A being
connected in any of the usual ways to the plates of the commutator C, each of the
brushes B is connected in the manner shewn to the coils M of the field magnets and
through them to the leads L which communicate with the generator. By this
arrangement the reversals of polarity in the field magnets and in the armature are
rendered synchronous, whatever be the rate at which these reversals occur.
Fig. 2 is a diagram illustrating the manner in which a machine having an
armature A of the disc kind can have its magnetic fields produced by coils M alone

page_text: without iron cores, the sychronion of the reversals of polarity in both the magnet and
the armature coils being produced by connecting the brushes B to the leads L through
the field coils M in a manner similar to that indicated in Fig. 1.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is
-
1. In an electro-motor adapted to be worked by alternating currents, connecting
the commutator brushes through the field magnet coils to the leads from and to the
generator, so that alternations of current produce synchronous alternations of polarity
of the field magnets and of the armature coils, substantially as and for the purpose
set forth.
2. In an electro-motor operating in the manner referred to in the preceding claim
dispensing with cores for the field magnets by arranging the field coils so as to
envelope the armature coils substantially as described.
Dated this 6th do..
ABEL & IMRAY,
Agents for the Applicant.