IMPROVEMENTS IN APPARATUS FOR GENERATING AND UTILIZING ELECTRIC CURRENTS
Year: 1883

page_text: LETTERS PATENT to Paget Higgs, of Leith, in the County of Edinburgh,
Electrician, for an Invention of "IMPROVEMENTS IN APPARATUS FOR
GENERATING AND UTILIZING ELECTRIC CURRENTS "
(Void by reason of the Patentee having neglected to file a Specification
in pursuance of the conditions of the Letters Patent.)
1
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PROVISIONAL SPECIFICATION left by the said Paget Higgs at the Office
of the Commissioners of Patents on the 14th August 1883.
PAGET HIGGS, of Leith, in the County of Edinburgh, Electrician, "IMPROVE-
MENTS IN APPARATUS FOR GENERATING AND UTILIZING ELECTRIC CURRENTS
"
My invention relates to dynamo or magneto electric machines which may be
used either as generators or motors.
One part of my said invention comprises improvements in the main frame of
the machine and consists essentially in the novel arrangement of the various parts
of the main frame whereby the cost of its construction is considerably reduced
Another part of my said invention comprises improvements in the construction
of the armature, and consists partly in arranging two rings side by side in such a
manner, that the currents which are induced in the said rings by the poles of the
field magnet are strengthened by the inductive action which takes place between
the rings as hereinafter described.
This part of my invention also includes a novel method of solidly fastening the
said armature rings to the hub which carries them.
It also comprises improvements in the construction of armature rings of the well
known "Puccinnotti " ог
"Gramme" type or form, whereby air is allowed to
circulate freely through and against the inner side of the iron of the same in order
to keep the ring.cool
According to the first part of my said invention I provide two oblong plates,
preferably of wrought iron, which form the ends of the frame of the machine;

page_text: these plates have recesses in their inner sides to lighten them and also to form
flanges on their edges, to these flanges are bolted flat bars of wrought iron, which
serve as cores for the field magnets. On the inner sides of these bars at the centre
of their length, are secured other pieces of wrought iron forming pole pieces,
between which the armature revolves. To the external sides of the said flat hars
opposite the said pole pieces are secured brackets of brass or other suitable metal,
which carry bearings for the shaft of the armature. It will be seen from the above
description that the frame is composed almost entirely of plain pieces of iron
which can be rolled to the desired size and fitted together with very little
difficulty and expense. This form of frame is especially applicable when the
armature is in the form of a ring
If the armature is of cylindrical form, the flat bars, instead of being arranged
upon the sides of the end pieces, will be arranged upon the top and bottom thereof,
and instead of the end pieces hereinbefore described I may use pillars of cast iron,
having bolts running through them longitudinally and through the said flat bars.
For carrying the armature shaft, bars of angle iron are bolted to the lower flat bar
of the frame having their flanges face to face. The said bars are turned upward
on each side of the frame to a vertical position and aro also inclined towards each
other to leave a suitable space for the shaft bearings. The said bearings are
supported by gibs and cotters below, and at the top are keys to tighten them.
This use of angle iron is novel and inexpensive, and combines great strength
with rigidity and lightness.
In constructing an armaturo according to this invention I provide two annular
cores of cast iron each of which has integral therewith wedge shaped. portions
which project radially beyond the inner periphery of the core and are broader than
the same. These wedge shaped portions of the two rings are placed adjacent to
each other and have formed on their inner edges slots or grooves which are adapted
to receive the extremities of arms or spokes (attached to a hub on the shaft) which
support the said rings.
These cores after they have been separately wound with wire are placed one on
each side of the said hub so that the ends of the spokes enter the recesses in the
wedge shaped portions, through which bolts are passed to secure the rings together.
Keys are suitably arranged between the bottoms of the recesses and the extremities
of the arms in order to entirely obviate any liability to slip.
: When an armature composed of two rings as herein before described is placed in
a machine, each ring will be excited on one side only, but it is well known that
the same electro motive force would be generated whether an armature be rotated
between two similar poles, one opposite each face of the armature, or before. a
single pole of double the intensity of one of the said two poles. I have applied
this principle in my improved machine by using two armature rings as hereinbefore
described each of which is only excited on one side, but as the said rings are wound
in the same direction, and are excited at similar parts by magnets of like polarity,
the currents generated therein are in the same direction, and, as the two rings are
placed side by side, the current in one ring induces a current in the adjacent ring
in the same direction as that induced by the magnet -so that the currents induced
by the field magnets are strengthened or increased by the action and re-action of
the armature rings upon each other.
By so arranging the connections of the wire of the field 'magnets as to make the
inducing poles all of one polarity, and by causing the armature to assume the
opposite polarity I can obtain a current flowing constantly in one direction in the
armature wire, which current being carried to two insulated rings on the shaft, can
be taken off by two contact brushes as a continuous current without commu-
tation on an ordinary divided or segmental commutator, as in the machines of tho
"Gramme" type. In this ease the current in the armature is due to the wire
thereof cutting the lines of force on one side and to the mutual inductive action on
the other side of the same ring

page_text: I will now describe the construction of the "Gramme" armature according to
this invention. The said armatures as generally heretofore constructed have been
mounted upon wooden hubs, which have been liable to shrinkage to such an
extent that the armature becomes loose. Moreover they have been very liable to
beat on the inner surface of the ring when the machine is running
According to this part of my invention I entirely dispenso with the wooden hub
and allow the air to circulate freely between the wires. For these purposes I
provide two flat rings of metal, connected by a number of cross bars attached to
them noar their inner peripheries I thus form what may be termed a cage, which is
mounted on a shaft by means of suitable arms or spokes.. In the outer peripheries
of the said rings and coinciding with each other are a number of transverse grooves.
The iron wire which is to form the core of the armature is wound around the said
connecting bars concentric with the axis of the said armature, so that a space is
left between the inner side of the said core and inner peripheries of the flat rings.
The induction wire of the armature is wound longitudinally with the axis, and is
laid in the said transverse grooves and then carried around within the rings, lying
upon the inner peripheries thereof. By making the armature in this manuer open
spaces are formed between the different portions of the induction wire and also
between the iron core and the induction wire.
If desired the wire may, with suitable modifications in the shape of the rings be
wound in the following manner, that is to say, by laying the alternate turns upon
the inner periphery of the rings upon each other, in this case the whole external
surface of the rings would be covered the air only circulating between the wire on
the inner side of the rings and the core.