IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES
Year: 1882

page_text: LETTERS PATENT to Frederick Leopold Willard Electrician 85 Hoxton Street
London N for an invention of IMPROVEMENTS IN DYNAMO ELECTRIC
MACHINES
PROVISIONAL SPECIFICATION left by the said Frederick Leopold Willard
at the Office of the Commissioners of Patents on the 14th June 1882.
FREDERICK LEOPOLD WILLARD Electrician 85
IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES
Hoxton St London N.
My Invention consists of improvements in Dynamo Electric Machines. As the
current derivable from the revolving armature is dependent upon the intensity of
the magnetic field and the closeness with which such armature can be made to
revolve within it. 1 so construct my field or inducing magnets, as to shroud or
close in the armature, on nearly all sides, The Field Magnets may consist of cast,
or wrought, or malleable iron, and they are wound in such a manner, as to cause
the poles to have an intense magnetic effect upon the armature revolving within
them. The armature consists of several cast or wrought or malleable iron rings,
having collars, shrunk or forged upon their sides, so that the coils which are wound
in the spaces between such collars, may be brought out flush; or level with such
collars, Lugs are cast, or forged upon the sides of these rings, for the purpose of
bolting them together; and the whole are then bolted to two brass cheek plates,
through which a fixed pin or spindle passes, and on which the cheek-plates with
the armature composed of the Lefore described rings turns.
My Field Magnets are so arranged as to produce an inductive effect upon both
the front, back and nearly the whole of the sides of the coils of wire wound in the
recesses between the collars before described. I produce in fact by my arrange-
ment an internal, and external field, the only part of the wire coils not directly acted
upon, being that composing the web, or lugs by which each separate ring is bolted
to its fellow. The Internal Field Magnet also carries the spindles upon which the
cheek plates, and armature turn. I attach my commutator to the cheek plates
which are carefully insulated from it, and to avoid sparking I construct it of a
J

page_text: series of wedge shaped plates, using two or 4, or more brushes, placed at right
angles or nearly so to each other, by arranging them thus, I collect the current in
smaller quantity, and so prevent the tendency to spark, which is usual with
commutators constructed in the ordinary manner; I sometimes couple up each
separate ring to an independent commutator, so as to use one, or more for the 5
purpose of exciting the machine, the rest being used for external work; or I may
pass the whole current collected by the commutators through the field
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederick Leopold Willard in the Great Seal Patent Office on the
14th December 1882.
FREDERICK LEOPOLD WILLARD Electrician of 85 Hoxton Street Hoxton
London N IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES
My Invention relates to improvements in Dynamo Electric Machines. The
current obtainable from the revolving armature of a dynamo machine is in a great
measure dependent upon the intensity of the magnetic field, The closeness with
which the armature can be made to revolve within it, and the construction of such
armature. The object of my invention is to so surround the revolving armature
by the Field or inducing magnets that it shall receive nearly all the inductive
effect they are capable of giving off. Instead therefore of relying upon an external
field only as is usual, I provide an internal field and cause the wire wound upon
the underside, as well as upon the external surface of the armature to be brought
under its influence, and so to speak cut a double magnetic field. The Field
Magnets may consist of wrought, cast, or malleable iron, or they can be made of
steel and be hardened so as to form permanent magnets, and cause an uniform
magnetic field They can be wound in the ordinary manner, as a series dynamo,
and the whole current can be sent round them, or part of it, the balance being used
for external purposes or they can be wound as a shunt, so that a very small portion
of the current is used. The internal field is wound longitudinally as a Siemens
armature and can also be shunted or form part of the main circuit. This internal
Field which is similar to a Siemens armature, that is it consists of a bobbin of
iron with a deep groove cut in it longitudinally which is filled with wire, so that
when excited by a current passing round it, it becomes a powerful magnet acting
inductively upon the underside of the wire forming the arinature coils. It is held
in place by a steel or iron rod passing through its centre, and upon this rod or
spindle the armature turns, The spindle is fixed, and passes through bushes in the
arms carrying the armature. The armature consists of several cast or wrought or
malleable iron rings, having collars, cast or wrought, or forged upon them, or they
can be shrunk on the rings, such collars being for the purpose of holding up the
wire, which is laid in the spaces between them, and also for increasing the
magnetic effect upon the armature by giving increased surface. Lugs are again

page_text: cast or forged upon these rings for the purpose of bolting them together, or the
V shaped pieces can be halved out so that the ring may be united by passing bolts
through such lugs or V pieces, the whole number of rings, are then bolted to two
brass or other non magnetic cheek plates, through which the fixed pin carrying
the internal armature passes and upon which such check plates and armature
turns. Outside the cheek plates my commutator is fixed, and to avoid sparking
and loss of current, I build it up of a series of wedge shaped plates using two, or
four, or more brushes placed at right angles to each other, or nearly so,
current is thus taken off by the commutator brushes, in smaller quantity and henco
the sparking is cut down to a minimum. Each ring forming the armature can be
coupled to a separate or independent commutator, or the whole series of rings to
one commutator, as already described. If coupled in single or double rings, to
independent commutators, part of the current may be taken from one ring, or
more to excite the field, the remainder being used for external purposes, or any
suitable division as between Field and outside circuit can be arranged
The
I will now proceed to explain my invention more fully by means of the
drawing.
Figs 1 Figs 2. shew side and front sectional views of my improvements, A A A
are the external field magnets, and B B the internal field-the end view of which
unwound is shewn at Fig 1, part section in Fig 2, and end view filled in with
wire in section, at Fig 3. The armature is shewn unwound at C Fig 1, with another
form shewing the flanges, method of joining to check plates, and the way in which
the rings are fastened at, C, C, C, C, fig 2, D D are the spokes carrying a ring, o.
a solid check plate may be used, to which the small rings are bolted. To one end
of these spokes, or cheek plates, fastened to a hub the pulley E is shewn, while
the other end is lengthened out into a sleeve, and is made to carry the commu-
tator F, which however is insulated from it by ebonite G. This sleeve is bored
out sufficiently large to allow the wires from the armature to pass through it. Its
outside surface forms the journal, turning in the pedestal H while the hub carrying
the pulley at the other end, is bored so as to turn freely upon the spindle I, which
supports the internal field B, and is held firmly fixed, in the independent bearings J,
which are bolted to the standards EI, and frame K. Fig 4 shews a method of
mounting I employ for small dynamo machines, A A is the field, the internal
field B being bolted to it by means of a disc plate furnished with a hub, or boss at M,
through which the spindle I passes. Attached to the other end of spindle I is a boss
carrying spokes D D, these are bolted to the armature rings CC; and when the
spindle I revolves, these rings revolve with it, between the internal and external
field, the commutator is placed outside the boss, carrying the spokes or cast in one
piece with them at D D, the driving pulley being keyed to spindle I.
Fig G
Fig 5 shews a skeleton ring, several of which form the armature, the ring is
joined by bolting at N, the V pieces being halved out for the purpose,
shews a section of my improved dynamo machine, identical with figure 2, but
having the commutator fixed inside the standards H H. The armature CC shewn
at figure 2 is also omitted, and also the top and bottom pole pieces of the external
field, in order that the internal field magnets B and its mounting upon the fixed
spindle I, may be more clearly seen. The commutator G is fixed to the arms or
disc D, but insulated from it, and the wires from the arinature sections are. lead
direct to its leaves. The internal field is shunted from the commutator, Fig 7
shews two of the rings forming my armature, and the method of connecting to the
commutator G'. The segment O is connected to its fellow P. the inner wire of
one section to the outer of the next, the other end of the wire in segment O is now
connected to plate 1 in the commutator, while the other end of segment P is
connected to plate 3, One end of segment Q, in second ring is connected to its
fellow R inner to outer as before described, while the other end is connected to
plate 2. The other wire of R being connected to plate 5, Both rings can bo
coupled together, or any number forming the armature or the wire can be laid
the full length of all the rings, forming the armature, to suit circumstances.

page_text: Figs 8 and 9 shew the form of commutator I employ. It is built up of alternate V
shaped pieces S which are fastened in any convenient manner to an insulated hub,
or collar, through which the sleeve and internal spindle pass. The brushes aro
arranged as shewn at T
Having now described my invention as well as I am able. I would have it
understood that I do not confine myself to the precise details shewn, and described
as they can be varied in many ways without departing from the peculiar features
of my invention, What I claim is
1st The combination in a dynamo electric machine, of an armature composed of a
series of rings of cast iron, soft steel; wrought iron, malleable iron bolted
together and supported by check plates or arms such armature being caused to
revolve between the poles of an internal and external field as described, and
shewn at Figs 1. 2. 4. 6 as and for the purposes set forth.
2nd. The arrangement of armature, and field magnet shewn at Fig 4, whereby the
internal and external field, is formed by connecting them together, by the disc
shewn. The armature revolving upon, or with the spindle I, such spindle being
supported on one side, by the disc and turning in an independent bearing on
the other.
3rd The arrangement for fastening the rings together as shewn and described
Fig 5
4th The combination in a dynamo electric machine of the rings, and commutator
shewn at Fig 7. The segments being coupled to alternate plates in the
commutator as described.
5th The combination of alternate V shaped segments, shewn at fig 8 & 9 with the
arrangement for collecting the current therefrom, by means of two, or four, or
more bushes, as shewn and described
In Witness whereof I The said Frederick Leopold Willard, have hereunto
set my hand and seal, this thirteenth day of December in the year of our
Lord 1882
Witness
FRANCIS M ROGERS
21 Finsbury Pavt
E.C.
FREDERICK LEOPOLD WILLARD (L.s.)