IMPROVEMENTS IN AND RELATING FOR DYNAMO OR MAGNETO ELECTRIC MACHINES " TO COMMUTATORS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Henry Ryan Lewis and William
Charles Smythe at the Office of the Commissioners of Patents on the
23rd August 1882.
HENRY RYAN LEWIS, of Bartholomew Lane, in the City of London, Mining
Engineer, and WILLIAM CHARLES SMYTHE, of Haymarket, in the County of
Middlesex, Engineer, "IMPROVEMENTS IN AND RELATING
FOR DYNAMO OR MAGNETO ELECTRIC MACHINES
"
TO COMMUTATORS
Our invention relates to commutators for dynamo or magneto electric machines
and is designed to increase the efficiency of such machines and make them more
readily applicable, than heretofore, to various kinds of work.
By a machine to which our invention is applied several circuits can be maintained
simultaneously for supplying lamps of different kind or construction, that is to say,
either arc, incandescent, or semi-incandescent lamps, and when a machine is used
for supplying one circuit only, a greater number of lamps can be maintained than
by any dynamo or magneto electric machine hitherto in use.
In these machines, as at present constructed, the full producing power of the
electro-motive force of the machine is not utilized in consequence of the sections
being coupled in multiple arc or divided circuit and there is a considerable loss or
waste of the actual electro-motive force developed by the machine.
According to our invention the plates of the commutator and the brushes are so
arranged that the sections of the revolving armature, in passing the neutral points
of the magnetic field, are cut out of circuit, and the whole of the various currents
generated by the remaining sections of the revolving armature can be collected and
arranged either for quantity or tension as required, or any number of the said
sections can be used to excite the field-magnets, and the remaining sections can be
arranged for tension or quantity as required, and alternating currents can also be
obtained.
In joining up the revolving sections, previously to connecting to the commutator
plates, (unless very low internal resistance be required or high tension is not
particularly required) diametrically opposite sections of the revolving armature are
connected for tension; the two remaining ends of these sections are then joined to

page_text: two sets of the commutator plates; these diametrically opposite sections then act
as one section or coil.
The end of each of such sections which is under the influence of the electro-
magnet is, by the commutator plates, caused to communicate with independent
metallic brushes. The ends of these brushes are connected to binding screws
marked with their respective numbers according to their position and potential on
the revolving commutator. The sections passing the neutral points are not in
communication with the brushes and the ends of the section are insulated so that
no currents can pass through them. If the whole of the sections under the
influence of the magnets are connected for tension the section or coil which has
next to pass the neutral points becomes an end section on the commutator; one
end of this coil becomes one end of the total revolving coil or armature which is
then connected to the field magnet coils; the other end of the field magnet coils
*becomes one terminal for the external circuit; the other end of the said section of
the revolving coil is joined to the next section thereof, whose electrical potential is
of different nature.
The end of the second section is joined to one end of the third section whose
electrical potential is of different nature; the other end of the third section, if there
are only four sections in the armature, becomes the other end of the revolving coil,
and therefore the other terminal for the external circuit.
We provide for exciting the field-magnets directly by having the ends joined to
the required number of revolving sections, which revolving sections may be
connected for quantity or tension as required.