IMPROVEMENTS IN DYNAMO OR MAGNETO ELECTRIC MACHINES
Year: 1882

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 DYNAMO OR MAGNETO ELECTRIC MACHINES" Communi-
cated to him from abroad by Jonas Wenström, of Örebro, Sweden, Civil
Engineer.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 10th October 1882.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake and Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN DYNAMO OR MAGNETO
ELECTRIC MACHINES," (A. communication to him from abroad by Jonas Wenström, of
Örebro, Sweden, Civil Engineer.]
The object of this invention is to utilize in dynamo-electric machines the excited
magnetism more completely than is done in such machines as heretofore constructed,
whereby I am enabled to reduce the quantity of the exciting current and the
resistance therein; and get the same result by less velocity and power and thereby
reduce the cost of construction and maintenance
The said invention relates both to the field magnets and to the armatures of the
said machines.
The electro-magnets heretofore employed generally consist of iron cores covered
with wire. In magnets so constructed a large quantity of magnetism is excited
round about them, and, as this magnetism is not utilized, great loss is occasioned.
In magnets constructed according to the said invention the bulk of the wire is
enveloped in iron and the excited magnetism in all directions will meet iron
capable of conducting it to the place where it is required. The said iron serves at
the same time to firmly unite all the stationary parts of the machine and allows
the armature to move freely between the polar surfaces or extensions.
According to one modification the magnet coils are enclosed between iron
cylinders which with their extensions form the frame as well as the magnet poles.
According to another modification disc-shaped copper coils are placed on a plain iron-
plate and the frame cylinder also surrounds the coil. In another form a number of
ID 31

page_text: disc-shaped coils are enclosed in iron and placed.side by side. The dissimilarity of
the poles is obtained in the following manner, that is to say, the poles of one
polarity project from one disc, and those of the other polarity from the next disc.
In order to allow of cooling the machine, space for the circulation of air is left
between each pair of the said discs. Bearings of dia-magnetic metal are bolted on
the outside polar projections. In another modification one wire coil is laid between
the frine cylinder and two semi-cylindrical poles.
In all the above mentioned modifications of field magnets, the copper coils are so
arranged that the electric current excites magnetism of one polarity in one set of
poles and of opposito polarity in the other set of poles.
The above described method of enclosing the copper wire coils in iron casings,
which at the same time form the frame, may also be applied to other dynamo-
electric machines.
The iron cores of the revolving magnets or armatures in the machines hitherto
employed are separated from the surface of the poles by the copper coils or the core
comes close to the poles at a small portion of its surface only. According to this
invention the core presents nearly the whole of its surface to the influence of the
poles by means of the conductors for the electric current being sunk in channels of
suitable form in the said core, the opening of which is a narrow taporing slit which
is filled with dia-magnetic material.
The iron core of the armature is either solid or composed of sections. In one
arrangement the iron core is fixed on the axle and each coil occupies the half of
two channels on opposite sides of the armature.
In another arrangement the iron core, in the form of a ring, is fixed on the axle
by diamagnetic metal and the channels are cut on the outside, the wire lying in
them and returning on the smooth inside surface of the core.
In another arrange-
ment the cores are fixed on the shaft by discs of non-magnetic metal. If the cores
are made of sheet iron they are coiled on concentrically from strips. The induction
coils are here inserted in radial grooves opposite each other on the flat sides of the
disc-shaped core. If more than one disc is put in, the coils must be distributed.
The magnet poles are as near the discs of the armature as possible. In another
arrangement every coil occupies the half of two adjacent channels on the same side
of the core.
When several annular discs are placed on the same axle their induction coils
are consecutively connected with the bars of the commutator
Armatures made according to this invention are also applicable for use with
permanent steel-magnets
The above described field magnets and armatures may be arranged in com-
bination in various manners or they may be used with armatures or field inagnets
of other suitable construction, and they may be adapted for machines operating
with alternating currents with one or more circuits:

page_text: invention
Figures 7 and 8 are a vertical longitudinal and a transverse section respectively
illustrating another modification
Figure 9 is a detail view of the same
Figures 10 and 11 are a vertical transverse and a longitudinal section respectively
illustrating another modification of the said invention
Figures 12, 13 and 14 are views hereinafter described
Similar letters of reference indicate corresponding parts throughout the
drawing.
c indicates the frame of the machine; d, d, the bearings; mm the field-magnets;
ww the insulated magnet-coils; and n, 8 the magnet poles. Between the said
poles on the shaft a revolves the armature which consists of the iron core k and
the coils in connection with the commutator f where the electric current is
collected and returned by the brushes e, e. b is the pulley for applying the force.
The electro-magnets as heretofore employed generally consist of iron cores
covered with wire. In magnets so constructed a large quantity of magnetism is
excited round about them and as this magnetism is not utilized great loss is
occasioned. In magnets constructed according to the said invention the bulk of
the wire is enveloped in iron and the excited magnetism in all directions will meet
iron capable of conducting it to the place where it is required. The said iron
serves at the same time to firmly unite all the stationary parts of the machine and
allows the armature to move freely between the polar surfaces or extensions
In the arrangement shown in Figures 1 2 3 and 12 the magnet coils ware
enclosed between iron cylinders c and m, which, with their extensions, form the
frame as well as the magnet poles n and 8. Figure 12 represents the method of
arranging two pairs of poles.
According to a modification shown in Figures 456 and 13 disc-shaped copper
coils w are placed on the plain iron plate m and the frame cylinder c also surrounds
the coil, as indicated by the dotted lines, Figure 13 shows the manner of arranging
four poles.
According to another modification shewn in Figures 7, 8 and 9 several disc-

page_text: shaped coils are enclosed in iron and placed side by side In the drawing three
pairs of poles are shown but it is obvious that a greater or less number may be
used as required. The dissimilarity of the poles, is obtained in the following
manner that is to say the poles n n of one polarity, project from the disc m, m;
and those 8, 8 of the other polarity from the disc c, c
In order to allow of cooling
the machine, space for the circulation of air is left between each pair of the
said discs. Bearings d of dia amagnetic metal are bolted on the outside polar
projections r.
According to another modification shown in Figures 10 and 11 one wire coil..
is laid between the frame cylinder c and the poles n and 8. In the drawing only
one pair of poles is shown, but it is obvious that more may be used.
In all the above mentioned modifications of field-magnets, the copper coils are so
arranged that the electric current excites magnetism of one polarity in the poles m, n,
and of opposite polarity in the poles 8. 8
The above described inethod of enclosing the copper wire coils in iron casings
which at the same time form tho frame, may also be applied to other dynamo-
electric machines
The iron cores of the revolving magnets or armatures in the machines hitherto
employed are separated from the surface of the poles by the copper wire coils; or
the core comes close to the poles at a small portion of its surface only
According to the said invention, the core presents nearly the whole of its surface
to the influence of the poles by reason of the conductors for the electric current
being sunk in channels of cylindrical, hexagonal, or other suitable form in the
said core, the opening to the said channels being narrow tapering slits which are
filled with diamagnetic material.
The iron core of the armature may be either solid or composed of sections
According to one arrangement shown in Figures 1 and 2 the iron core is fixed
on the axle and each coil occupies the half of two channels on opposite sides of tho
armature
In another arrangement shown in Figures 4 and 5 the iron core in the form of a
ring is fixed on the axle by diamagnetic metal and the channels are cut on the
outside of the core only, the wire lying in them and returning on the smooth inner
surface of the said core.
In another arrangement shown in Figures 7, 8, and 9 the cores are fixed on the
shaft by discs of nonmagnetic metal. If the cores are made of sheet iron, they are
coiled on concentrically from strips. The induction coils are here inserted in radial
grooves, opposite each other on the flat sides of the disc shaped core shown in
Figure 9. If more than one disc is put in, the coils must be distributed, as shown
in Figure 14. The magnet poles have projections 7. which are arranged as near
the discs as possible
In another arrangement shown in Figure 13 every coil occupies the half of two
adjacent channels on the same side of the core.
When several annular discs pp, Figure 14 are placed on the same axle, their
induction coils are consecutively connected with the bars q, q of the commutator,
as shown.
Armatures made according to this invention are also applicable for use with
permanent steel magnets
The above described field magnets and armatures may be arranged in com-
bination in various manners or they may be used with armatures or field-magnets
of other suitable construction; and they may be adapted for machines operating
with alternating currents with one or more circuits:
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. In a dynamo or magneto electric machine, enclosing the coils of the field-
magnets within an iron casing or covering substantially as and for the purposes
.set forth

page_text: Second. The said iron casing or covering constructed in such a manner as to
form the frame of the machine and one or more pairs of poles or polar extensions,
substantially as described
Third. The field-magnets constructed substantially as described with reference
to either of the modifications illustrated in Figures 1 to 6, 12 and 13
Fourth. The field-magnets constructed substantially as described with reference
to Figures 7, 8 and 9, and having the discs separated by air-spaces, as above set
forth for the purpose specified
Fifth. In a dynamo or magneto electric machine, forming channels for the
electrical conductors in the core of the armature, in such a manner that only
narrow slits interrupt the surface of the core, and filling these slits with dia-
magnetic substance substantially as, and for the purpose, specified.
Sixth. In an annular disc armature, the separate rings in combination with, and
connected to, the commutator, substantially as described with reference to
Figure 14 for the purpose specified.
Seventh. In a dynamo electric machine provided with an annular disc armature
as above described, forming the poles with projections embracing the armature
rings substantially as set forth
Eighth. The field-magnets and armatures constructed as above described with
reference to the drawing and combined with each other, or with armatures or field-
magnets of other suitable construction, substantially as set forth.
In Witness whereof I the said William Robert Lake have hereunto set my
'hand and seal this Tenth day of April in the year of Our Lord One
thousand eight hundred and eighty three