IMPROVEMENTS IN MAGNETO-ELECTRIC. MACHINES
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN MAGNETO-ELECTRIC. MACHINES." A communication from
abroad by Charles A. Seeley, of the City and State of New York, United
States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 14th May 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN MAGNETO-ELECTRIC
MACHINES." A communication from abroad by Charles A. Seeley, of the City and
State of New York, United States of America.
This Invention relates partly to an armature which is made as nearly as practi-
cable in the form of a disc, and revolves between magnetic poles of opposite name.
It may in short be considered a modification of the device known as "Arago's disc,"
whereby the induced currents of the disc are rendered utilizable.
In the common form of this disc device the induced currents find in the con-
ducting matter of the disc direct paths of reunion, and thus the electricity is almost
wholly transformed into heat, while in my disc armature the currents produced in
precisely the same condition are kept apart and carried away. I secure this result
by suitably constructing the disc of insulated wire.
The said Invention is illustrated in the accompanying Drawing, in which,―
Figure 1 is a perspective view of a machine constructed according to this
Invention.
The remaining Figures shew details of the said machine, and are hereinafter
described.
Like letters indicate the same parts throughout the Drawing.
If a vertical wire be moved in front of a north magnet pole to the right the
induced current tends upward, and if the wire be so moved before a south magnet
pole the current tends downward; and if the wire be moved in an opposite direc-
tion before the poles the current will tend in reversed directions. In Figure 5 a
wire is represented as bent, so that a large part of its course is on radial lines.
Now if there is placed behind the wire, as at A and C, north magnet poles, and
-

page_text: behind the wire, as at B and D, south magnet poles, and the wire is revolved around
its horizontal axis, the induced current will throughout the length of the wire tend
in the direction shown by the arrow until in its revolution the wire comes under
the controlling influence of the poles of opposite names, when the current will be
reversed. In the arrangement illustrated in Figure 5 during one complete revolution
the current will undergo four reversals.
It is evident that by increasing the number of magnet poles in the series, and of
the corresponding wire segments, the electric changes will be correspondingly
increased; also, that in any arrangement the strength of the current is increased by
increasing the number of the wires. By reason of the number of poles therein I
term this apparatus "multipolar."
The said disc armature consists essentially of wires wound in radial directions, so
that the radii entering the armature in the winding may be moved before magnet
poles of the same name, while the outgoing radii will move before the opposite
poles.
It is to be understood that the whole mass of the disc so far as practicable must
be made up of the radial, winding, and that the sectors of outward and inward
winding shall be equal in number and symmetrical in form and arrangement.
A simple manner of winding is shown in Figure 4, where the radii at the left are
entering and the radii at the right are outgoing; in this case also the wire occupies
a section of one sixth of a circle, and six similar sectors are needed for the com-
pletion of a disc armature.
The manner of winding shown in Figure 4 may be so carried into effect that any
sector of a circle may be filled out, and constantly one half of the wire will be out-
going and one half incoming.
Another manner of winding is to continue the wire across or beyond the centre of
the circle, bending the wire away from the centre to clear the axis, and continuing
it diametrically in one direction and returning diametrically in another direction,
and so on until a whole sector is filled up; in this method the diametrical wires
cross each other near the centre. Several layers or spires of sectors may be laid or
wound upon each other, thus increasing the thickness of the disc and the quantity
of wire contained in it. Inasmuch however as the thickening of the disc necessitates
the separation of the magnet poles and a weakening of the magnetic field on the
disc the thickening must be restricted within narrow limits.
Figure 2 is a face view of the disc armature, and Figure 3 is a transverse section
through the centre of the same. E is the axis; F is the radial part of the winding;
G, G, are other parts of the winding; H, H, are circular plates or rings of
metal or other suitable material for binding in place the outer sides of the
sectors.
In Figure 3 N, N, S, S, are four magnets in the proper position relatively to the
armature; the disc revolves between magnets of opposed polarity.
There may be as many pairs of magnet poles as there are sectors, but as with
other armatures and for similar reasons the number of magnet poles may be varied.
The sectors of my armature bear the same relation to the field magnet as do the
components of other "multipolar" armatures, and they are susceptible of many
well known modifications in their arrangement; the aforesaid sectors may be
considered as serving in the place of belices of ordinary construction.
It will now be readily understood that these sectors may be connected in series
or in multiple arc, and be united with commutators of the ordinary construction.
For example, the said sectors are joined in series when the outer end of one is con-
nected with the inner end of the next, and they are joined in multiple arc when
the outer ends are brought together on one division of the commutator and the
inner ends on the other. The connections are not shown in the Drawing for the
reason that they are well known to those familiar with the subject to which this
Invention relates. It will be observed that only the radii or radial parts of the
wire of my armature are efficient for the electro-magnetic induction, while the cir-
cumferential parts serve only as connectors for the radii; the distinction of efficient

page_text: or radial and connecting or curved wire will be of assistance in the understanding
of this Invention.
The radial wire only is comprised within the magnetic field; it is desirable that
this radial or efficient wire shall be as compact in form as possible, and that no
substance other than this efficient wire shall occupy space in the magnetic field.
The connecting wire on the other hand should be entirely beyond or out of the
magnetic field, and should serve as the medium of support for the whole structure.
The binding circles or rings I, I, and rings H, H, by means of pins, screws, or
bolts firmly keep together the united sectors; the said armature may be attached
to the axis by any well known or ordinary means.
Figure 6 is a plan of the "multipolar " field magnets in which one half of the
system comprising six magnetic poles is shown. The faces of the poles are set
radially to conform to the armature, and are all in the same plane. It is advan-
tageous to form these "multipolar" magnet cores of a single piece of cast iron.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,―
First. A magneto electric machine in which the efficient portions of the wire of
the armature revolve within the magnetic field, and the connecting portions of the
wire revolve without or beyond the magnetic field, as and for the purpose specified.
Second. The combination of the binding rings I, I, and the rings or circles H, H,
with the other parts of the armature, substantially as and for the purpose specified.
Third. The "multipolar " field magnet core cast in a single piece.
Fourth. The manner of winding the armature, substantially as described, whereby
the magnetic field may be occupied by the efficient wire.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Fourteenth day of May, in the year of our. Lord
One thousand eight hundred and eighty.