An Improvement in Dynamo Electric Machines.
Year: 1890

page_text: Date of Application, 9th Dec., 1890
Complete Specification Left, 9th Sept., 1891-Accepted, 7th Nov., 1891
PROVISIONAL SPECIFICATION.
An Improvement in Dynamo Electric Machines.
I, ARTHUR SALISBURY BAXENDALE, of the Straits Settlements, Super-
intendent of Posts and Telegraphs, do hereby declare the nature of this invention
to be as follows:--
My invention relates to a construction and arrangement of dynamo electric
machines. Instead of arranging bobbins of insulated wire on a revolving armature,
I attach such bobbins to oscillating arms by which they are moved to and fro in
magnetic fields. When in an electric generator the fields are those of permanent
magnets or of electromagnets of constant polarity, the moving bobbins give
alternating currents which may be commutated into continuous currents. I prefer,
however, to commutate the currents which excite the field magnets, so that the
bobbins as they move to and fro give continuous currents.
In like manner in an electro-motor, either the currents for the bobbins or those
for the field magnets may be commutated.
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The commutators employed, instead of being of the rotary kind as in ordinary"
machines having revolving armatures, are of a reciprocating kind, making and
breaking contacts by their to and fro strokes.
Dated this 9th day of December 1890.
ABEL & IMKAI,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Dynamo Electric Machines.
I, ARTHUR SALISBURY BAXENDALE, of the Straits Settlements, Super-
intendent of Posts and Telegraphs, 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:-
My invention relates to a construction and arrangement of a dynamo electric
machine. Instead of arranging bobbins of insulated wire on a revolving armature,
I attach such bobbins to oscillating arms by which they are moved to and fro in
magnetic fields.
When the fields are those of permanent magnets or of electromagnets of constant
polarity, the moving bobbins give alternating currents which may be commutated
into continuous currents. I prefer, however, to commutate the currents which
excite the field magnets, so that the bobbins, as they move to and fro, give con-
tinuous currents.
Figure 1 of the accompanying drawing is a front elevation, Figure 2 is an end
elevation, and Figure is a plan of one form of dynamo electric machine according
to my invention.
Figures 4, 5 and 6 are corresponding views of a modified form of the machine.
In all these figures similar letters are employed to indicate corresponding parts.
Referring first to Figures 1, 2 and 3 M M are magnets either permanent or
electromagnets, having pole pieces P which are hollowed out to allow bobbins B
wound with insulated wire to reciprocate vertically between each pair of the pole
pieces. These bobbins B, are fixed at opposite ends of a lever L which is caused
to oscillate by the ratchet teeth of two wheels W acting alternately on antifriction
rollers R on the lever L, these wheels being on an axis caused to rotate by a band
acting on a pulley Q or otherwise. As shewn in Figures 4, 5 and 6, there are

page_text: four bobbins B and four magnets M each bobbin reciprocating between a pair of
pole pieces P. The bobbins B are on arms A of a rocking shaft S, other arms C
on which are acted on by the ratchet teeth of a revolving wheel W. In both forms
of machine, if the magnets M are permanent, or if they are electromagnets of
constant polarity, the ascent and descent of the bobbins B between these poles
generate alternating currents in the wires of the bobbins. These currents may be
converted into currents of one direction by means of a suitable commutator having
segments corresponding to the teeth of the wheels W, on the axis of which it may
be fixed with suitable collecting brushes bearing on it. If the magnets M change
their polarity with every stroke of the bobbins, then the currents in the wires of
the bobbins B will be of one direction. It is however preferred to maintain
constant polarity of the magnets; and to excite them by the commutated currents
from the bobbins. The magnets may have compound winding, part in the mair
circuit and part in a shunt in the well known manner.
When the bobbins B are fixed on the lever L or the arm A they necessarily
move. in circular paths. The pole pieces P have then to be hollowed in a form to
correspond with those paths. The bobbins however might be jointed to the lever
or arms and guided to move in straight paths.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
A dynamo electric machine wherein by the revolution of a double or single
toothed wheel one or two pairs of bobbins of insulated wire are caused to reciprocate
between magnetic poles, substantially as herein described.
Dated this 9th day of September 1891.
ABEL & IMRAY,
Agents for the Applicant.