An Improved Electric Motor or Dynamo-electrio Machine.
Year: 1896

page_text: Date of Application, 19th Aug., 1896
Complete Specification Left, 26th Apr., 1897-Accepted, 19th June, 1897
Kingdom of Italy, Engineer.]
An Improved Electric Motor or Dynamo-electrio Machine.
I, JOHN THOMAS KNOWLES, Trade Marks Agent, of the Firm of D. Young & Co.,
of 11 and 12 Southampton Buildings, London, W.C., do hereby declare the nature
of this invention to be as follows:-
The electric motor which forms the subject of the present application is chiofly
designed for use in the propulsion of tramway vehicles; it is however also capable
of other applications.
The improved motor is constructed as follows:-Two armatures similar to those
of a continuous-current Gramme machine and with bi-polar winding, are arranged
side by side, with their axes of rotation parallel, in such a manner that they cannot
come into contact with one another.
The field-magnet winding is arranged in the centre, in a position which is
symmetrical relatively to the longitudinal axes of the said armatures, the plane of the
coil or coils being preferably parallel thereto; it thus follows that the two armatures
form the core of the field magnet coils or solenoid. The magnetic circuit is
preferably completed externally by means of a ring having pole-pieces on the outer
sides of the two armatures.
A pole-piece which is sometimes made double (being formed by two pieces
arranged symmetrically, one above and the other below) serves to close or complete
the magnetic circuit between the two armatures; this pole-piece can however be
formed in a single piece by increasing the distance between the axes of the two
armatures. In this case there will be four separate air-spaces in the magnetic
circuit. The armatures are absolutely independent of one another; in cases whore
they are applied to tramway vehicles, one serves to drive the front wheels and the
other tho rear wheels of the vehicle. The said motor is reversible, and can be
employed as a dynamo or generator of current.
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.
An Improved Electric Motor or Dynamo-electric machine.
I, JOHN THOMAS KNOWLES, Trade Marks Agent, of the Firm of D. Young & Co.,
11 and 12 Southampton Buildings, London, W.C., 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 electric motor which forms the subject of the present application is chiefly

page_text: designed for use in the propulsion of tramway vehicles; it is however also capable
of other applications.
It is shown in the accompanying drawing, in which
Figure 1 is a vertical longitudinal section on the line A. F, Figure 2, and
Figure 2 is a vertical transverse section on the line C D, Figure 1.
The improved motor is constructed as follows:-Two armatures M, N similar to
those of a continuous-current Gramme machine and with bi-polar winding, aro
arranged side by side, with their axos of rotation parallel, in such a manner that
they cannot come into contact with one another.
The field-magnet winding O is arranged in the centre, in a position which is
symmetrical relatively to the longitudinal nxes of the said armatures, the plane of
the coil or coils being preferably parallel thereto; it thus follows that the two
armatures form the core of the field magnet coil or solenoid O. The magnetic
circuit is preferably completed externally by means of a ring R having pole-pieces
on the outer sides of the two armatures.
A pole-piece P, which in the drawing, is double (being formed by two pieces
arranged symmetrically, one above and the other below) serves to close or complete
the magnetic circuit between the two armatures; this pole-piece can howover be
formed in a single piece by increasing the distance between the axes of the two
armatures. In this case there will be four separate air-spaces in the magnetic
circuit. The armatures are absolutely independent of one another; in cases where
they are applied to tramway vehicles, one serves to drive the front wheels and the
other the rear wheels of the vehiclo. The said motor is reversible, and can be
employed as a dynamo or generator of current.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
An electric motor comprising two independent armatures having their axes
of rotation parallel, and a single field-magnet, the winding of which is arranged
in a symmetrical position relatively to the said armatures and in a direction
parallel to their longitudinal axes, substantially as herein before described.
Dated this 28th day of April 1897.
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.