AN IMPROVED ELECTRO-MOTIVE EXON
Year: 1881

page_text: LETTERS PATENT to Desiré Thomas Piot, of Great Titchfield Street, in the
County of Middlesex, for an Invention of "AN IMPROVED ELECTRO-MOTIVE
EXON"
PROVISIONAL SPECIFICATION left by the said Desiré Thomas Piot at the
Office of the Commissioners of Patents on the 5th November 1881.
DESIRE THOMAS PIOT, of Great Titchfield Street, in the County of Middlesex.
"AN IMPROVED ELECTRO-MOTIVE ENGINE."
My Invention relates to an electro-motive engine, and it has for its object to
enable a greater length of wire to be wound on the coils of the armature without
increasing or even whilst reducing the distance at which the electrical attractions
and repulsions between the field electro magnet or magnets and the armature take
place, whereby the motive power of the machine is greatly increased.
My improved machine consists of one or more field electro magnets radial to the
armature axis, and of an armature composed of a number of coils arranged around
and parallel to a common axis of rotation. The coils are wound circularly in the
ordinary way upon soft iron cores, which are cranked at each end of the coil, and
connected at their extremities to discs mounted upon a shaft or axis. The cranked
portion of the several cores carrying the coil turns between the poles of the field
electro-magnet or magnets, and the straight end portions of the cores together
form a cylindrical part of the armature of smaller diameter which turns opposite
lateral polar extensions of the field magnet or magnets corresponding to the length
of that part of the armature.
The armature coils are connected with the corresponding parts of two com-
mutators, and are successively traversed by currents alternately in opposite
directions, the field magnet or magnets being constantly excited by a current from
a battery, accumulator, or other suitable electric source.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Desiré Thomas Piot in the Great Seal Patent Office on the
5th May 1882:
DESIRE THOMAS PIOT, of Great Titchfield Street, in the County of Middlesex.
"AN IMPROVED ELECTRIC MOTIVE ENGINE."
My Invention relates to an electric motive engine, and it has for its object to
enable a greater length of wire to be wound on the coils of the armature without
increasing the distance at which the electrical attractions and repulsions between
the field electro naguet or magnets and the armature take place, whereby the
motive power of the machine is greatly increased.
My improved machine consists of one or more field electro magnets radial to the
armature axis, and of an armature composed of a number of coils arranged around
and parallel to a common axis of rotation. The coils are wound circularly in the
ordinary way upon soft iron cores which are cranked at each end of the coil, and
connected at their extremities to discs mounted upon a shaft or axis. The cranked
portions of the several cores carrying the coils turn between the poles of the field
electro magnet_or_magnets_and_the_straight_end_portions_of_the_cores together form
a cylindrical part of the armature of smaller diameter, which turns opposite lateral
polar extensions of the field magnets or magnets corresponding to the length of that
part of the armature.
And in order to explain my said Invention more fully I will now proceed to
describe the same, with reference to the accompanying Sheets of Drawings, in
which the same letters denote the same parts in all the Figures.
At Sheet 1, Figure 1 shews a longitudinal section through line H, H, on on
Figure 2, Sheet 2, of an electric motive engine constructed according to my said
Invention.
At Sheet 2, Fig. 2 shows an end elevation, and Figure 3 a cross section of
same.
At Sheet 3, Figs. 4, 5, 6, 7, 8, and 9 shew details hereinafter referred to
drawn to a larger scale than Figs. 1, 2, and 3.
With reference to Sheets 1 and 2, A, A, are two frames bolted on to bed
plate B, and bolted together by pillars C carrying a shaft D. To these standards
are fixed the field electro magnets E at equal distances apart, and on the shaft D
are keyed discs of brass or other nonmagnetic material F, F, carrying the coils
or bobbins G forming the armature, these bobbins being also equidistant on the
discs. The cores of the field magnets E are composed of soft iron, and on these cores
a properly insulated conducting wire (of copper by preference) is coiled circularly
(preferably about five layers) and insulated also from the iron cores. The iron
cores of the field magnets E are of a crank shape so as to form polar extensions a,
and the cores of the bobbins G are also cranked as shewn at to work between
the poles or polar extensions a of the field magnets E, and turned up at b so as to
work opposite the ends of the polar extensions a, as shewn. The cranked
extensions a and b of the cores of bobbins and magnets are left bare, and these
extensions are so adjusted that the outer edges of the cores 6 of the armature
revolve as closely as possible to the inner edges of the polar extensions a of the
field magnets. These edges of a and bare formed by preference pointed, as

page_text: shewn by Fig. 8, Sheet 3, or of such configuration as to offer as little resistance
as possible when the extensions b of the bobbins G pass the polar extensions a of.
the field magnets E.
I will now proceed to describe the commutator and its various connections,
shewn at Figs. 4, 5, 6, 7, 8, and 9, on Sheet 3, for working my improved electric
motive engine without roversing the current, which is preferable to using any
commutator or commutators producing alternate currents in opposite directions,
because in the former case the coils are not liable to become heated. At Fig. 5,
Sheet 3, d is a disc formed of wood or other suitable insulating material fastened
to the aforesaid disc F, so as to revolve therewith. On the periphery of this disc d
are fixed at equal distances apart a number of metal plates e (made of copper or
other suitable conducting metal) corresponding to the number of bobbins in the
armature. These plates must all be of the same length on periphery of disc d.
The wire from each bobbin at one end is connected with one of the metal plates e
on the disc d, and also connected with the wire from the bobbin, which is radially
opposite to it in order to make electrical communication. Four rollers f, f, f, f, and
two rollers g and g¹ are kept in contact with the periphery of the disc d, as shewn
at Fig. 9, Sheet 3. The rollers f work freely on frames h, h, which are in commu-
nication with one pole of the electric current by means of wire ȧ. These rollers
are kept in forced contact with the periphery of the disc d by means of the spring k
acting on frames h, k, which are pivoted at l. The other rollers and gare placed
so as to come exactly opposite two of the rollers f, and are similarly kept in contact
with the periphery of disc d. The frames h, h, and h', h', are pivoted on brackets m,
which are attached to a block n composed of wood or other insulating material, so
as to entirely insulate rollers f from rollers g. The rollers g and gl convey part
of the same electric current to the field magnets by means of the plates, e
on disc d, which plates are electrically influenced by the rollers f. The block n is
fitted with a handle p, Fig. 2, and is so placed on frame A as to be capable of being
turned either to riglit or left, so as to move the frames h, h, and h', h', which carry
rollers fand g and g' a certain distance round the periphery of disc d, as hereafter
described. The other pole of the electric current communicate with the other
ends of the bobbins of the armature and the field magnets by means of the roller 8
mounted on a pivoted arm t, and kept in contact with disc r by spring u. Tho
arm t is pivoted to bracket v, which is attached to a block of wood or other
insulating material, all shewn clearly at Figs. 4 and 6.
All the wires of the field magnets E at one end and the wire from one pole of
the electrical current are put into communication with the arm tat w, and the
bobbins of the armature are also put in connection with the same pole by means
of the roller 8 running on the metal disc r, which is in contact with the wires x
coming from the bobbins G, so that part of the current from this pole goes into the
field magnets E and part into the bobbins of armature. In order to complete the
circuit the other electric pole is put in communication with the commutator at
the other end of the machine by means of wires i. The bobbins, which are set
opposite each other, are connected together by their wires, which wires commu-
nicate with their respective plates e on disc d, as shewn at Figs. 5 and 8,
Sbeet 3.
At that end of the machine marked Z, Sheet 1, the ends of the wires from the
alternate field magnets, marked 10, 12, 14, 16, on Fig. 2, Sheet 2, are in electric
communication with one of the rollers g, Fig. 7, Sheet 3, and the other magnets,
marked 11, 13, 15, 17, are in electric communication with the other roller g' by
means of wires o and o¹, Fig. 7, respectively, and with the plates e on disc d, Fig. 9.
The action is as follows:-
Upon making electrical communication the armature will revolve, carrying with
it disc d, thus making and breaking electric contact with magnets and bobbins of
armature at the proper times.
In order to reverse the action of the machine or form a brake it is simply
necessary to move handle p in the required direction, thus shifting the position of

page_text: rollers f, g, and g¹ with regard to the plates e on the disc d, thereby changing the
electrical communication.
I would here remark that although I have described and shewn an electric
motive engine in which the armature revolves (as being preferable) it is evident
that by modifying the construction the electro magnets may be made to revolve
and the armature remain stationary.
If it is desired to work this machine by an alternating current it must be
provided with two suitable commutators, which it is unnecessary to describe.
Having thus described and ascertained the nature and object of my said Inven-
tion, and the manner of carrying the same into practical effect, I would remark in
conclusion that I do not intend to limit myself to the various details or to the
number of magnets or bobbins described and shewn on Drawings; but what I
claim as my Invention, and desire to secure by the herein before in part recited
Letters Patent, is,―
Firstly. The use substantially as described of crank shaped soft iron cores wound
circularly with insulating conducting wire, these forming the coils or bobbins of
the armature, such coils or bobbins being arranged so that the several extended
cores thereof may come between and also opposite the ends of the polar extensions
of the field electro magnet or magnets, substantially as set forth.
Secondly. The arrangement of field electro magnets, substantially as and for the
purposes set forth.
In witness whereof, I, the said Désiré Thomas Piot, have hereunto set my
hand and seal, this Fifth day of May, in the year of our Lord One thousand