IMPROVEMENTS IN DYNAMO- ELECTRIC POWER CREATING MACHINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by John Edward Tenison Woods at the
Office of the Commissioners of Patents on the 19th August 1882.
JOHN EDWARD TENISON WOODS of 19 South Grove Peckham Rye in the
County of Surrey Electrical and Civil Engineer IMPROVEMENTS IN DYNAMO-
ELECTRIC POWER CREATING MACHINES
The objects of my invention are to manufacture Dynamo Electric Power
creating Machines on new, Improved and economical principles, either for Electric
Lighting purposes or for the transmission of power whereby increased effect
diminshed weight and space and consequent economy in the motive power
employed is secured
My invention consists of improvements in several parts of the machines as well
as the introduction of new principles in the machines themselves to those hitherto
in use with the objects specified above
In the first instance the soft iron cores of the circuit magnets and of the field
magnets (where soft iron is used) are formed of parallel lengths of the softest
homogenous iron wire which may be of any size convenient to the purpose
These are tied in bundles and are heated nearly to welding temperature in
pulverised oxides of Iron by which they are rendered still softer-While still
heated they are removed from the furnace and with as little exposure to the air
as possible are passed through grooved rollers of suitable size or swedged on the
Anvil with a grooved Mandril which has the effect of pressing the round wires
close together making them assume more or less a hexagonal or six sided form
without disturbing the direction of the longitudinal fibre of the iron wires used
upon which the rapidity that the iron cores acquire and throw off their induced
magnetism so much depends
The second part of my invention consists in winding the soft iron cores so
formed as above for the field magnets or circuit magnets as the case may be with
wire drawn through a square die and properly insulated by any of the well known
modes now in use By this arrangement greatly increased conductivity in the
wire used is obtained with a diminution of space occupied by the coil (which
under usual circumstances amounts to one fourth of the coil space employed) and
thus pro tanto increasing the power obtained from coils of the same size as those
wound with ordinary round wire.

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The third part of my invention consists in forming a circle of five or more field
magnets constructed with core and surrounded by coils of conducting wire as
above specified so as to form a whole Cylinder of a size according to the power
required to be developed. In the interior of this Cylinder of field magnets is
placed another cylinder of soft iron plate of sufficient thickness to acquire the
necessary magnetic induction which will vary according to the size and power of
the Machine This Cylinder is formed of a bent soft iron plate supported by arms
upon an axis so as to revolve freely but it is not closed or welded at the junction
or point of the circle where the two ends of the plate meet so as to avoid the
circulation of Electric currents in the Cylinder itself―This interior Cylinder is
furnished with five or move indentations longitudinally in which is coiled the
square insulated wire above mentioned so as to be perfectly flush or even with the
surface of the Cylinder so that the whole Cylinder with its coils revolves close to
the poles of the field magnets above mentioned The ends of the wires wound in
these indentations as above described are carried to the commutators on each end
of the spindle axis so as to utilise the induced currents produced therein by the
revolution of the interior cylinder as above described in front of the Field magnets
before mentioned
A Shunt arrangement is attached to the spindle by which a portion of the
induced current created is passed through the wires surrounding the Field magnets
to produce the inducing effect on their soft iron cores above described-The
simple revolution of the interior plate Cylinder on its spindle axis at an angle
with the magnetic meridian of the earth is sufficient to excite a current in the
wires laid in its indentations above mentioned so as to charge the field magnets of
the machine through the shunt
The fourth part of my invention consists in having the Field Magnets constructed
as above mentioned of a cranked form or low arc with large flat terminals five or
more of which are arranged round the external portion of the machine in a
longitudinal direction.
An equal number of Circuit coils and cores constructed as above are inverted
upon the revolving spindle also having flat terminals which during revolution
pass in close contact with the poles of the Field magnets as above described.
Similar arrangements of the commutators and shunting apparatus are employed as
above mentioned and for the same purposes
The fifth part of my invention consists in placing the Field magnets as mentioned
in the fourth part of this specification of the same core and wire above described
but arranging the Circuit Magnets with coils so that the poles are fixed between and
are placed alternately with the poles of the field magnets at a distance varying
according to the size of the machine but sufficient to allow of the passage of the
soft iron armatures presently to be described-both Circuit magnets and field
'magnets being fixed and immoveable-On each end of the moveable axis revolving
in the centre of the machine which carries the Commutators and shunting arrange-
ment above described are placed Wheels or discs of metal-These wheels or discs
carry an equal number of oblong soft iron armatures corresponding with the field
magnets horizontally arranged and projecting inwards from the peripheries so as
to revolve in the space between the respective poles of the Field Magnets and
Circuit magnets employed thus changing the induced magnetism of the Circuit
magnets rapidly and alternately as the wheels or discs revolve while the Field
Magnets and coils and Circuit magnets and Coils remain fixed and immoveable
In starting this machine it is necessary to create magnetism in the Field magnets
as above described either by auxiliary Battery power or a small exciter machine-
As both Field and Circuit magnets are fixed and do not revolve the inducing
magnetism of the earth cannot be taken advantage of in charging the field Coils
and magnets but when once the action is commenced by such necessary currents
of Electricity external to the machine itself and produced either by Battery power
or small exciter machines the action is continuous.
A small exciter Dynamo Electric machine of any of the forms before mentioned

page_text: can be placed on the moving axis carrying the armatures and commutators so as to
produce the necessary initial charging power to the field magnets by means of the
earth's magnetism and thus becomes practically self acting with a minimum
expenditure of the motive power.
It is obvious that permanent magnets of Steel magnetised in the ordinary
way may be used as the external Cylinder of Field Magnets in the arrangement
for the revolving armatures last described in which case there is no necessity for
a separate small exciter Dynamo Machine on the moveable axis carrying the discs
and the revolving armatures last described-I do not bind myself to any particular
size of the cores or wires used in the coils surrounding them but what I claim is
1st The improvements in the soft iron cores as above described
2nd The arrangement of the conducting wires of the coils of the form above
specified whether for the field or Circuit magnets and coils-By these means
greatly increased power of the Dynamo Electric machines made with these coils is
obtained but occupying a dimished space
3rd The means of creating Electric power by more economical methods by the
agency of the various forms of Apparatii as above described to be utilised either
for Electrical lighting power or other purposes