IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1884

page_text: COMPLETE SPECIFICATION.
"
I WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the
nature of my invention for "IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to dynamo-electric machines not having iron in the
rotating armatures, and has for its objects, firstly to produce a powerful induced
current by means of a disc revolving between field-magnets and consisting of
peculiarly arranged radial strips of copper connected by other strips running in
circular directions to form circuits for the current to circulate many times in
opposite directions through the said radial strips; Secondly, to arrange the said
connecting strips in relation to the field-magnets in such a way, that useful
currents are induced in the same as well as in the radial ones; thirdly, to so
arrange the field magnets, that they will act with their north poles on the one side,
and with their south poles on the other side of the armature; fourthly, to arrange
the armature and commutator in such a manner that the said strips can bo
connected in various ways, to act more or less in serios or in parallel to vary tho
electro-motive force of the current produced; and fifthly, to so construct the frame
of the machine, that the armature and the shaft can be easily removed, without
taking the frame apart.
I attain these objects by the mechanism illustrated in the accompanying
drawings in which :
Figure 1 is a vertical section of the entire machine.
Figure 2, shows a partial front view and on the right hand side a partial vertical
section on the line 1-2 Figure 1.
Figures 3, 4, 5 and 6 are views illustrating the construction of the commutator.
The remaining Figures are views of details and diagrams for explaining the
construction and action of the armature.
Similar letters refer to similar parts in all figures.
The parts A and E constitute the frame of the machine. B is the main shaft with
the double flange C, by which the armature disc D is connected to the shaft by

page_text: screws, ns is shown in Figure. 1; an insulating substance being placed between the
flange and disc.
To the standards E E are fastened the field magnets G and F, which are wound
with insulated copper wire, so that their poles are opposite to the ones facing thein,
that is to say, so that a north pole on the one side will face a south pole situated
on the other side, but in the same line. At the same side of the disc D the poles
are north and south alternately.
All the poles may face towards the disc, as the magnets G G. (Figure 1), and in
this case they are alternating on each side; or the magnets may be so arranged,
that every second pair of facing magnets is connected by a bridge piece F, as is
shown by the connected magnets F F.
The poles of the magnets are thereby closed, and cannot act on the disc D; but
the magnetism induced in them by their coils, increases the power of the open
poles of the next magnets, forming with them S magnets, with all the north poles
on the one side of the disc, and all the south poles on the other side, thus making
very powerful magnets of considerable length.
1 11
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In the figures, 16 magnets are shown on each side, but more or less may be used.
The disc Dis constructed in the following manner; P. P, Figures 9 and 10
indicate radial strips, and R.R, Figures 9 and 11 the connections, which have the
form of segments and have their ends bent angularly; The said connections are
soldered (or rivetted) to the radial strips P, P in the way shown in Figures 12, 13
and 14 at the points a b c to form a circle. The point d is not connected to the
strip P, but remains open. A second similar circle is then made with the
connections R R their bent ends being somewhat shorter, so that the said
circle can be laid within the first one, a narrow strip of insulating material being
,placed between, so that the parts do not touch each other anywhere. The end d
of the first circle is then connected to the strip P₁ of the first circle, while at a the
second circle remains again free.
A current which flows in through the strip P, circulates therefore twice around,
viz. once through the parts P₁ R₁ P₁ R₁ of the first circle and then through the
same parts of the second.
11
In the same manner five (or more or less) of such circles are laid within each
other and connected as explained, so that the current must circulate as often in
going through each section, of which there are 64, each consisting of 10 radial
strips P, and 10 connections R, R₁₁. These sections are then combined to form a
disc, as is shewn in Figures 7, 8 and 9. They are fastened by the flange C
clamping the inner ends of the radial strips P.
Figure 8 shews the outer circumference of the disc (supposed to be stretched out
flat) and explains how the different sections are connected, so as not to interfere
with each other. Figures 1 and 8 shew sections of the disc, and Figure 9 is a
partial front view of the same.
To give room for the connections R₁ R₁₁ to pass one another, there are on each
side two rows of them outside the pole pieces, and two rows inside. In Figure 8
only one, namely the outside row, can be seen; the white square spaces are
supposed to contain the radial strips P of the inner row. All the parts are insulated
by narrow strips, but so that the air can freely circulate around them.
The angular distance from a to y (Figures 8 and 9) of each section must-be
equal to the angular distance from one field magnet to the other viz, 11th of the
circle, and as there are 64 sections, there will be four distinct series, which come
⚫ one after the other under the influence of all magnets. There are four circuits or
currents, each of which must pass through 160 radial strips P, back and forth,
before it reaches the commutator, in which these alternating currents are converted
into a continuous one.
The different sections are connected by separate pieces like the pieces R, which
separate pieces are situated at the inner ends of some of the radial pieces P'within
the flange C, and are not shewn in the drawing. To explain how the current is
induced in the radial strips P by the motion in the magnetic field, I will now

page_text: consider only a single circlo on its way between the magnets, and suppose that the
_inner connections R₁ do not return to the same section, but go on towards the next
so that the inner connections go in the directions shewn by the thick lines in
Figure 17. Further let it be supposed for the sake of simplicity that the line of
the magnets and motion of the disc is a straight one from left to right and that
the magnets are all like those G G with open poles so that there are south and
north poles on each sido as is indicated in the diagrams Figures 15 to 20 by 8
and n. The poles facing the disc on one side are indicated by shaded squares, and
the directions of the magnetic currents (according to Ampère's hypothesis) by fine
arrows; the armature is shewn by thick lines, and the direction of the current
induced in it, by arrow points drawn into this line. The diagram 15 shows the
radial parts P, P₁ situated in the middle between two poles. P₁ is retreating
from the magnetic currents of the south pole on its left side which there run
downwards; this tends to induce a downward current in it; but it is also
approaching the downward currents of the north pole at its right side, which tends
to induce an upward current; no induction can therefore come into effect and this
is the neutral position when the current is cut out by the commutator. In all
situations the part P₁, is acted on exactly the same as P, only the directions of tho
currents are opposite, and so also in all the following parts belonging to the same
series.
11
11
Figure 16 shews the radial part P, at the edge of the north pole.
As the space
between the south and north poles is filled with vertical magnetic currents down-
wards P, retreats from a greater number of such currents, than it approaches,
therefore a downward current. is induced in it. This is further assisted by its
approach towards the upward currents on the right side of the north pole n, which
excites also a downward current.
Figure 17 shews P₁ in the middle of the pole, which is the best position; it is
now retreating from all the downward magnetic currents at its left side, and
approaching towards all the upward currents at its right side; both of these actions
induce in Pa powerful current in a downward direction.
The next position Figure 18 is similar to Figure 16. P₁ now approaches more
downward currents than it is retreating from, and is also retreating from the
downward currents of the north pole at its left side, which induces a downward
current in it. The position following next is like Figure 15, being again neutral,
and as P₁ goes on further the same induction takes place in the same order, but in
an opposite direction. There are consequently as many alternations of the current
during one revolution of the disc D, as there are magnets on one side of it..
If the magnets are arranged so that the poles of every second pair are connected
like those F F in Figure 1, then all the poles on one side of the armature will be
alike, and the action as follows.
Figure 19 is the neutral position of P₁, which is now situated at the edge of the
pole. As all the poles are south poles, their magnetic currents change directions in
the middle between them, as well as in the middle of the polo; P₁ is therefore
retreating from as many downward currents, as it is approaching, consequently no
current is induced.
11
In Figure 20, which is the best position, P, is in the middle of the pole,
retreating from the upward currents at its left side, and approaching the downward
ones on its right side, which induces an upward current. P₁ is situated between
two equal poles and also retreats from the downward currents of the magnet at its
left and approaches the upward currents at its right hand side, which induces a
downward current in it. Both arrangements of the magnets give about the
same effects.
The peculiar situations of the connections R, R₁ close to the edges inside and
outside of the pole-pieces (Figure 1) produce also induced currents in them during
their motion, which induced currents assist the induced currents in the radial
parts P₁, the said currents being simultaneous and of equal, direction.

page_text: When a current (be it electric or magnetic) is flowing towards a conductor, or
away from the same, in an angular direction, and if the conductor is moved in the
direction of its length, a current is induced in it, whose direction is equal to the
motion when the inducing current is passing away from the said conductor, and
opposite when the current is passing towards it.
Now in the position Figure 17, the magnetic currents between the poles s and n
are flowing downwards, that is away from the connection R₁ which causes the
induction of a current in it equal to the direction of its motion. In the connec
tion R₁ below, the same action takes place. When the parts have moved the full
distance from one magnet to the next, the magnetic currents flow every where
If the
towards R, R₁₁ which induces in a contrary direction to the motion.
connections R₁ pass towards the left side, (towards P, as in Figure 12) to form
the circles, then they are also induced in the direction, that the induced current
will correspond with the one induced in all other parts, as will be seen by
examination. The inductions which have been explained above for the single
circles, are simultaneously going on in all others that belong to the 16 sections
forming, one series, and the 4 series follow one another so that while one is neutral
the other three are more or less in action, and one of the latter in the best position.
Each series may be entirely separate, and have both ends directly connected to the
commutator; or all 4 series may be connected together, so as to form one circuit,
and connections shunted off from them at different places, which connections are
led to the commutator. The more such shunts are led off the more are the
sections connected in parallel, and the less shunts are made the more sections aro
combined into series and the higher will be the electro motive force of the current
generated.
Figures 3, 4, 5 and 6 are detail views of the commutator L; Figure 4, shows one
of the 8 rings, out of which the collector disc is made up: Two of such rings
belong to a series; a cable leads from each end of the series to the hole whercin it
is fastened. The two rings belonging together are combined, so as to have their
· outside projections (of which there are 8 on cach ring) 1/10th of a circle apart, so
that the two form 16 projections in equal divisions. The 4 pairs are then combined
and fastened between flanges, (as is shown in Figure 5, which is a longitudinal
section) to form the collector disc with 64 projections, an air space being left
between each, and an insulator placed between the 8 rings. The projections slant
towards the axis, as shown in Figure 6, which is the surface of the disc stretched
out flat. The object of this slant is to have the brushes touch two of the projections
at once.
The positive and negative brushes must touch the projections at an angular
distance from each other, which is 1, 3, 5, 7, 9, 11, 13 or 15 sixteenths of a circle.
The signs and indicate in Figure 8 the distance, within which the currents
change direction.
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If the connections between the armature and the commutator are shunted off, as
above explained, then I prefer to make the projections straight instead of oblique
so that each brush touches only one of these projections at a time. By adjusting
then the brushes so that they are one projection more or less apart, as the unequal
numbers of sixteenths above given, the brushes do not touch two rings belonging
together at the same moment, but rings belonging to two series next to each other.
The induced current inust therefore circulate through two series before it can pass
out through the brushes, as one of the pair of rings L is cut out, when the other is
in contact; the current can therefore not pass out through the two ends of the
series, but must pass over to, and circulate through, the next series, where it is
again strengthed by induction, after which it passes to the brush through one of
the rings belonging to the second series.
こ
There will then remain always two series connected one after the other in contact
with the brushes, and when a new one coines in contact a former one is cut out, and
one remains with the new one. This variation of the connections may be extended
further by making the armature with more than 4 series.

page_text: I generally use more than two brushes, and up to 16 may be distributed around
the commutator to prevent undue heating.
The parts P and R may be flat, square or round in section and be arranged in
other ways than here explained without departing from the nature of this inven-
tion. The connections R₁ R₁ may have their flat sides facing towards the centre
of the disc.
The different segments and circles may be so combined that they move along as
mentioned with reference to the diagrams. Figures 15 to 20, the different circles
being then also laid together as in Figure 7, so that the parts lie side by side
without crossing each other, and so that the parts R₁ R₁ run close to the edges of
the magnets.
The numbers of the magnets and of the parts in the armature and commutator
may be other than as shown in the drawings.
To remove the shaft with the armature and commutator without requiring the
magnet standards E E to be taken off, I make these standards open on the top, so
that the shaft can freely pass out. These openings are closed by segments e e,
screwed to the standards; one or two magnets is or are fastened to each of these
segments, and removed with them.
This machine may be used as a motor.
Having now particularly described and ascertained the nature of my
Invention, and in what manner the same is to be performed I declare that what
I claim is
First. The armature disc formed of radial parts P which are insulated from each
other and held to the shaft by means of the double flange C, and combined by
segmental connections R₁ R₁₁ into circles, each of which has about an angular length
y equal to the angular distance from one pole to the other; said circles being
again combined into sections, and these again into several series, as described.
Second. The arrangement of the connections R₁ R₁₁ in an armature, having the
form of a disc or a drum, so that they pass each other without crossing, and that
they move close to the edges of the pole pieces, whereby useful currents are induced
in the same, as described.
Third. The arrangement of the field-magnets with the bridge connection, so that
4 of them will form one S magnet and have on one side of the armature only free
south poles and on the other side only free north poles, as described.
Fourth. The construction of the collector disc, and of a series of rings L, Figure 4,
as described.
Fifth. In a machine having no magnets or iron in the rotating armature, the
combination of all the series of the armature disc into one continuous circuit, and
the leading off of shunt connections to the commutator, whereby the current can
be forced to pass through more than one series, by varying these connections or the
positions of the brushes on the commutator, as described.
Sixth. The arrangement of the standards E, to facilitate the removal of the main
shaft as described.
noted this 8th dow of Novemba 198A
HASELTINE, LAKE & Co.,
For the Applicant.