IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES A
Year: 1883

page_text: LETTERS PATENT to Henry Harris Lake, of the firm of Haseltine, Lake, and.
Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES A communication to him
from abroad by George Washington Fuller, of Norwich, Connecticut, United
States of America.
""
COMPLETE SPECIFICATION filed by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 13th March 1883.
Patent
HENRY HARRIS LAKE, of the firm of Haseltine, Lake, & Co,
Agents, Southampton Buildings, London, "IMPROVEMENTS IN DYNAMO-ELECTRIC
MACHINES Communicated to me from abroad by George Washington Fuller of
Norwich, Connecticut, United States of America
This invention relates to certain special features of construction in the dynamo-
electric machines, employing an armature core which is independent of the coils
surrounding it, and which is inade to preserve unchanging polar relations to the
field magnets.
In the specification of former Letters Patent dated March 12th A:D 1883
No 1313, I have described the armature core as employed in an alternating current
machine, and in a modification thereof as employed in a constant current machine,
in each of which the said armature core, which is in the form of an annulus, is
provided upon its periphery and sides with polar prominences, and is rotated by
the magnetic attraction of rotating field magnets arranged in circumposed groups,
each of which groups is composed of three magnets of like polarity to each other,
but of opposite polarity to that of the groups adjoining it.
In the present case the annular armature core, instead of having the polar
prominences upon its periphery and sides, is composed of two long segments of
iron, or other magnetic material, secured to two short segments of non-magnetic
material, and in the two circles of rotating field magnets the inagnets of like
polarity adjoin each other, and are united by common pole-pieces, those of the field
magnets which are of one polarity being upon one side of the axis of the machine,
and those of the other polarity being upon the other side thereof;

page_text: According to this invention, I employ two parallel systems of circumposed
rotating field magnets. The number of magnets in each system may be varied
according to the size of the machine. The magnets of the two systems are
respectively affixed to the opposed faces of two rotating discs, and their axes are
parallel to the axis of rotation of the said discs.
Between the opposed poles of the field magnets I support the armature coils
upon a stationary frame. The armature core which is segmentally encircled by
the armature coils, and is in the form of a flattened ring, is suspended in the bight
or bights of one or more cables or cords hung over a suitably elevated loose
pulley, and is prevented from swaying laterally by means of grooved guide
rollers acting through the spaces between the stationary coils upon the convex
portions of the cables, embracing the core. The core being thus free to rotate is
carried around by the attraction of the rotating field magnets, and its division into
segments of magnetic material causes the establishment in it of permanent poles at
the ends of the segments.
The coils of the field magnets and the armature coils are all included in the
same circuit, and the machine is self charging.
A peculiar commutator'and brushes are employed to collect the electrical currents
induced in the stationary coils, and by means of suitable contact makers and.
connections the current from the commutator is conducted through the field circuit
coils, and through the outside or working circuit.
In the accompanying drawings of a machine illustrating my invention, the
systems of rotating field magnets are each composed of but four magnets, two of
which of like polarity are upon one side of the shaft, while the other two, which
are of the opposite polarity are upon the other side of the shaft. The number of
magnets of which each system is composed may however be indefinitely increased,
according to the size of the machine.
Figure 1 is a side elevation of the said machine.
Figure 2 is a longitudinal vertical section, and
Figure 3 is an end elevation of the same.
Figure 4 is a transverse vertical section on the line Y, Y Figure 1.
Figure 5 is a transverse vertical section on the line W, W Figure 1.
Figure 6 is an elevation of a part of the frame supporting the stationary coils.
Figure 7 is a transverse vertical section on the line x, x Figure 2, showing in
elevation one of the systems of rotating field magnets and the two pole pieces
respectively connecting the poles of like polarity.
Figure 8 is a transverse section drawn to an enlarged scale showing the parts cut
by the line y, y on Figure 6.
Figure 9 is an elevation of the armature core, showing one of the stationary coils
enclosing a portion of it.
Figure 10 is a section of the armature core on the line, Figure 9.
Figure 11 is an axial section drawn to an enlarged scale, of the commutator and
adjoining parts of the machine.
Figure 12 is a transverse section of the commutator on the line 1, 1, Figure 11
showing the mode of securing the brushes to the rotating brush holders, and the
manner in which the brushes bear upon the concave faces of the stationary
commutator strips.
Figure 13 is a transverse section on the line 2, 2 Figure 11.
Figure 14 is a transverse section on the line 3, 3 Figure 11.
Figure 15 is a transverse section on the line 4, 4 Figure 11, representing
diagramatically the eight stationary armature coils, and showing the manner of
electrically connecting these coils with each other, and with the commutator strips.
Figure 16 is a diagram representing the coils of the rotating field magnets, and
showing the manner of electrically connecting such coils with each other and with
the contact wheels by means of which electrical connection is made with stationary
brushes.
The bed A is provided with the two standards B B¹, which are respectively

page_text: perforated to receive the opposite ends of the horizontal bolts b which project
respectively through the standards to receive the nuts b'.
The standards are respectively provided with the central bosses B2 B³ which are
perforated to receive the main shaft C of the machine which is driven by a belt
on the pulley C¹.
.
Secured on the shaft C between the standards, are the substantial hubs D d, to
which are fastened respectively the wheels D' and d', which carry the field.
magnets E, E, E¹, E', and F, F, F¹, F¹. The wheels D₁ and d' are fastened to their
respective hubs by screws D² ².
The cores of the field magnets are at one end fastened to the wheels D' and ď
respectively, by suitable numbers of screws D³, d³.
The axis of the field magnet cores are, it will he seen, parallel to the shaft C.
The pairs of adjoining magnets E, E, and E', E', F F and F' F', are provided with
the pole pieces e and e¹, fand f¹, respectively, which are severally fastened to the
field magnet cores by the screws e, e³ and f, f³ respectively.
The horizontal bolts b serve the further purpose of supporting the two annular
plates G g, to which the stationary armature coils H are secured. These plates are
each provided with outwardly projecting perforated ears, like the ears g¹ in
Figure 6, through which the bolts b are inserted, and with eight equidistant
inwardly projecting triangular ears 92, the relatively opposed sides of which are
parallel with each other and are provided with inclined flanges g³, to form the
bearings for the bevelled sides of the stationary coils H, as shown in Figure 8
Gibs are introduced at one side of each coil and set screws h² are inserted in the
flanges gå for setting up the gibs and firmly holding the coils in position. The
two plates G g are secured to each other by the bolts G¹.
The holes in the outwardly projecting ears g' of the plates Gg are made larger
than the bolts b and are each provided with the three set screws G³, G², G², the
inner ends of which bear upon the bolts b, in each case, for the purpose of affording
means for adjusting the position of the stationary coils H relatively to the position
of the armature core.
The stationary coils H are circumposed and loosely encircle sections of the
armature core I, hereinafter termed the floating core which is a flattened ring
composed of two long segments I, 12, of paramagnetic material, united at their ends
to two shorter segments I³, I of diamagnetic material, by the screws 2. The longer
segments may each be made of two plates i, i¹ and i³, i³ (as shown in Figure 10)
secured to each other by the screws i. The core I is suspended in the bight of.
three endless cords K, K, K, which are deposited in three parallel circumferential
grooves k, k, k, formed in the periphery of the core. The suspending cords are
hung over the elevated pulley K³, in the three circumferential grooves k¹, k¹, k
respectively. Any lateral sway of the core is prevented by means of the guide
rollers L, L' and L2, each of which also has three circumferential grooves for
engagement with the suspending cords respectively. It will be seen that the spaces
between the exterior edges of the stationary armature coils H expose sufficient
portions of the periphery of the core to permit the application of the guide rollers
as described.
The shaft of the lower guide roller has its bearing in the box M, supported by
the standards M¹ M², erected upon the bed of the machine. The shaft and l² of
the upper guide rollers have their bearings respectively in the boxes m m,
supported by means of the eye-bars m³, m' and m², m² upon the horizontal
bolts b, b, b, b.
-
The rollers or pulleys L' K' and L2, in addition to acting as idlers, and taking
up the slack of the suspending cords, also serve as means for effecting the lateral
adjustment of the core. To this end the holes in the eye-bars through which the
bolts bare inserted are made larger in diameter than the bolts, and the eye-bars
are provided with the adjusting screws M³, M³, B³, the ends of which, in each-
instance, bear upon the bolt b. It will be seen that by means of these adjusting
screws, either of the pulleys L' and L2 may be moved inwardly or outwardly, and

page_text: that by moving the pulley L¹ outwardly and the pulley L² inwardly, the core may
be swung to the right and vice versa by moving the pulley L' inwardly and the
pulley L2 outwardly, the core may be swung to the left.
The shaft of the elevated pulley K¹ has its bearing in the box 1, supported by
means of eye-bars upon the upper pair of horizontal bolts b,.b.
The coils of the field magnets of each group are so connected, that the pairs of
magnets having a common pole-piece are of like polarity to each other; the
magnets having their cores affixed to one pole-piece being of opposite polarity to
that of the magnets having their cores affixed to the other pole piece. The pole-
pieces which face each other are also of like polarity, the two pole-pieces upon one
side of the shaft being of one polarity, and the remaining pole-pieces upon the
opposite side of the shaft, being of the opposite polarity.
In Figure 16 which is a diagram illustrative of the manner in which the coils of
the field magnets may be so connected up as to be included in the same circuit,
there is a representation of the coils of the two groups of field magnets as they
would appear if the discs upon which they are respectively supported should be
swung around upon vertical axes in opposite directions so as to present the opposed
poles of the cores in the same plane. By following out the diagram showing the
convolutions of the coils, and the mode of connection of the coils with each other,
it will be seen that the upper pairs of the two groups of field magnets present
north poles toward each other and the lower pairs present south poles toward each
other.
The terminals N n of the field circuit are carried through apertures in the hub &
and are electrically connected respectively with the contact discs N°, n, which are
insulated from each other and from the main shaft C, upon which they are
mounted. The current for charging the field is transmitted to the contact
discs Non by the brushes N³ n². One of these brushes N2 is electrically connected
with the binding-post N³ on the lower end of the brush holder, which supports the
brush n² which bears upon the face of the contact wheel n mounted upon the
end c of the main shaft, but insulated therefrom and electrically connected with
the commutator brush holder n°. One terminal of the working circuit is connected
with the brush n² and the other terminal is connected with the binding-post N
on the lower end of the holder which supports the brush N2, which bears upon the
contact wheel N° mounted upon the end c of the main shaft, but insulated there-
from and electrically connected with the other commutator brush holder N. The
brush holder n is semi-cylindrical, the front end being secured to the contact
wheel n by the three screws nº. The brush-holder N also semi-cylindrical in
shape, is provided on its front end with three perforated bosses N8 which project
through the apertures n in the contact wheel n*, and which are tapped to receive
the three screws N° by which the brush holder N7 is secured to the contact
wheel No. The perforated bosses N are surrounded with tubular shields N° of
ipsulating material, by which they are insulated from the contact wheel n*.
The two contact wheels n' and N° are secured upon the end c of the shaft by
means of the nut c' which serves to clamp the contact wheels against the shoulder c²
formed upon the shaft C. It will be seen that the commutator brushes n and N",
which are affixed respectively to rotating brush holders n³ and N7, bear upon
the concave surfaces of the commutator strips o which are affixed to the interior of
the cylinder O¹, but are insulated therefrom and from each other. The brushes n³
and N" are respectively fastened by the screws n³ N12 to the top of the
ribs 10 N13, formed upon the exterior of the brush-holders no and N' respectively.
A shield of insulating material N¹³ is interposed between the end c of the shaft
and the concave surfaces of the brush holders. The inner ends are each provided
with pairs of projecting lugs, which are perforated to receive the screws N14 by
which the brush-holders are clamped together. Washers of insulating material N15,
are introduced between the lugs. The clamping screws N", N", which are screwed
into the lugs of the brush-holder N7, are suitably insulated from the brush-
holder No, as shown in Figure 12.

page_text: The commutator cylinder O¹, is fastened by the set-screws O? upon the projecting
end of the boss B³, in which the main shaft C has one of its bearings, and is
circumferentially adjustable. The ends of the screws 02 are conical and bear upon
the inwardly inclined bottom 03, of a circumferential groove in the periphery of
the boss B³, thus producing the effect of forcing the rear end 0 of the commutator
cylinder against the shoulder B of the boss B³, and thereby centralizing the com-
mutator cylinder. The strips o¹ are fastened to the cylinder by means of the
screws 0. A binding post of, is provided for each strip, and the number of strips
equals the number of stationary coils employed in the machine.
The stationary coils H are connected in series the outer convolution of one coil
being connected with the inner convolution of the next following coil, and so on,
thus making an endless conductor which includes all the stationary coils. Between
each pair of coils, the circuit is looped to the commutator strips, as illustrated in
Figure 15.
In Figures 17, 18, 19 and 20 I show a modification of this invention, in which
the floating core is an annulus composed entirely of soft iron or other magnetic
material, and is supported and centralized by means of the exteriorly placed rollers
which act upon its periphery through the spaces between the armature coils;
several of these rollers are adjustable for the purpose of centralizing the core.
A core thus constructed being free to move, is rotated by the attraction of the
rotating field magnets, but I also provide for its rotation by mechanical power,
imparted by one or more positively rotating friction rollers bearing upon its
periphery.
Except in the particulars hereinafter set forth in detail, the machine is the same
as that bereinbefore described, and therefore does not need especial description
except as to the particulars referred to.
Figure 17 is a sectional end view, and
. Figure 18 a detached sectional front view, illustrating the rolls as arranged for
mechanically driving the floating core I.
Figure 19 shows the cradle detached.
Figure 20 is a section of the floating armature core on the line Z Z
Figure 17.
The armature core I is a flattened ring, which, like that hereinbefore described,
is independent of the stationary coils which loosely inclose it. segmentally, but in
this instance it is composed entirely of a paramagnetic material, and constructed
however with a removable section, united to the principal section by tongued and
grooved joints. The removable section may be conveniently composed of shouldered
plates, see Figure 20, secured to each other by screws i², 22 and respectively
secured to the parts of the principal section which they overlap, by screws i³, i
The armature is provided upon its periphery with a shallow circumferential
groove I, for engaging with the peripheries of the wheels or rollers by which it is
centralized and supported or driven. Of these rollers the uppermost one P has a
bearing arranged similar to the upper pulley hereinbefore described and its shaft
has adjustable bearings, as before described.
The upper part of the groove I2 in the core is engaged by the peripheries of the
three driving rollers Qq and R, the central driving roller R is affixed to the end
of a shaft which is inserted through the box R¹ and the driving rollers are
likewise respectively secured to shafts which pass through the boxes Q¹q', and
have affixed to their opposite ends rollers, as seen in Figure, 18, in which the
roller Q is shown Q' being the roller upon the opposite end of the shaft. The
peripheries of these outer rollers engage with the circumferential groove D
formed in the periphery of the rotating magnet disc D¹, see Figure 18, the said
disc is secured to the hub D mounted on and revolving with the shaft C, as
hereinbefore described.
It will be understood that systems of toothed wheels may, if desired, be used in
the place of the described system of rollers, of friction wheels by which as will be.

page_text: Been, power derived from the shaft C is transmitted from the rotating disc D' and
made to rotate the armature core.
The boxes in which the shaft of the rollers have their bearings are all movable.
Thus the box R¹ is contained between two parallel vertical jaws in which it can
slide up and down. The boxes Q¹¹ are all held in parallel jaws which are
oppositely inclined toward the centre of the machine.
To
The boxes carrying the driving rollers are thus provided with guide bearings in
which, when they are being adjusted, they move in converging lines toward or
from the axis of the rotating core. It will be seen that the box R¹ is guided in
its movement up and down when being adjusted by the vertical jaws r, r.
move it up and down, it is provided with cross arms 71, 71 notched on their sides
near the ends, to receive the rounded upper ends of the push bars, the lower
rounded ends of which are located in the notches s formed respectively in the tops
of the cradles SS. The notches 8, s in each cradle are upon one side of its fulcrum,
and similar notchés s¹s are formed in the top of each cradle upon the opposite
side of its fulcrum. The two cradles are alike in construction, and are provided
at their ends respectively with cylindrical bosses S¹ S¹, see Figure 19, which
constitute their axis of oscillation. The boxes Q¹ q¹ of the said rollers are provided
with feet Q³ q³, the lower rounded ends of which are held in the notches s¹ in the
tops of the cradles respectively. The fulcrums of the cradles are the tops of the
wedge bars T T, one of which is represented in elevation in Figure 18, on reference.
to which Figure it will be seen that the bar T is horizontal upon the top and has
two inclined faces t, t upon its under side, which faces bear respectively upon
correspondingly inclined tops of two standards t', t¹ affixed to the bed of the
machine. The blunt end of the wedge bar abuts against the horizontal set
screw T', inserted laterally through the standard T. By turning in the set-
screw T', the top of the wedge bar T is raised, thus raising the cradle resting upon
it; and thereby forcing upward the friction rollers with which the cradle is
immediately connected. The bosses S S₁ of the cradles are guided in paths
inclined towards the axis of the rotating core respectively by inclined parallel
jaws S², S².
As each cradle is supported upon the top of an adjustable bar similar to that
shown in Figure 18, it will be seen that the rollers Q and q can be raised or
lowered independently of each other, and that by raising one and lowering the
other the core may be thrown over laterally in either direction as may be required
to bring the peripheries of the driving rollers Q, R and q against the periphery of
the core, or to centralize the core with relation to the interiors of the circumposed
stationary coils.
By this arrangement of driving rollers, the core is rotated by mechanical power
and at the same speed as that of the rotating magnets. The core however will be
rotated by the mere attractive force of the rotating field magnets without the aid
of mechanical power.
If desired therefore the adjustable rollers Q, R and q may
be employed merely as supporting and centralizing rollers, in which case the
rollers at the opposite end of the shaft, as Q2, will not be employed, and the ends
of the shafts on which they are mounted may be provided with bearings against
the under sides of adjustable hälf-boxes contained in suitably inclined guides, and
the rollers for centralizing and supporting the core may be mounted in a vertical
plane transversely bisecting the middle of each cradle, as indicated in dotted lines
in Figure 18. In such case the cradles would require to be moved toward the front
of the machine a sufficient distance to bring the middle of the cradles into the plane
of the core.
It will be seen that the two cradles serve as equalizing levers for equalizing the
pressure of the rollers Q R and q, upon the periphery of the armature core. The
weight of the armature resting directly upon the roller R, is transmitted to the
inner sides of the cradles or levers, which are thus depressed. The outer sides of
the cradles being correspondingly elevated, act upon the feet Q³ q³ and press the

page_text: rollers towards the axis of the core. Thus all three of the rollers QR and q
are made to do an equal amount of work in supporting or driving the armature
core.
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-electric machine provided with a suitable commutator and
suitable electrical connections, two parallel systems of rotating field magnets, a
system of circumposed stationary armature coils arranged between the opposed
poles of the two systems of field magnets and loosely encircling segments of a
floating armature core in the form of a flattened ring built up of segments of
magnetic material joined to segments of non magnetic material, as set forth.
Second. In a dynamo-electric machine, substantially of the character described,
in which the field magnets are rotated and the circumposed armature coils are
stationary, an annular armature core independent of the armature coils, and sus-
pended in the bight or bights of a cord or cords hung over an elevated pulley, and
prevented from swaying laterally by suitably grooved guide rollers, acting through
two or more of the spaces between the outer portions of the circumposed stationary
coils upon a cord or cords lying against the periphery of the annular core.
Third. In a dynamo-electric machine, substantially of the character described, in
which the field magnets are rotated and the circumposed armature coils arc
stationary, a stationary commutator cylinder provided with internally placed
insulated strips, suitably connected with the stationary coils and brushes mounted
upon and rotating with the shaft of the rotating field magnets, but insulated
therefrom and electrically connected with the field and working circuits, and
adapted to bear upon the concave faces of the commutator strips fastened to the
interior of the stationary commutator cylinder.
Fourth. In a commutator, substantially such as described, in which the com-
mutator strips are affixed to the interior of a stationary cylinder surrounding the
end of the rotating shaft upon which the rotating field magnets are mounted,
brush-holders in the form of semi-cylinders, partially embracing the said end of the
rotating shaft, and respectively fastened to and electrically connected with two
contact wheels, suitably insulated from each other, the contact wheels being
provided with stationary brushes by means of which the electrical impulses induced
in the stationary coils and collected by the rotating brushes are conducted to the
terminals of the field and working circuits.
Fifth. The adjustable pulleys L1, L2, bearing in opposite directions upon the
cords in the bights of which the armature core is suspended, for effecting the lateral
adjustment of the armature core.
Sixth. The frame for supporting the circumposed stationary coils H composed of
the plates G g, provided with means for adjusting the circumposed coils H relatively
to the annular core I.
Seventh. In a dynamo-electric machine in which the field magnets are rotated
and the armature coils are stationary, a suitably supported and centralized armature
core independent of the armature-coils, and one or more driving wheels having a
prescribed speed of rotation relatively to the speed of rotation of the field magnets,
for mechanically rotating the armature core.
Eighth. In a dynamo-electric machine, substantially such as described, employing
a floating armature core independent of the armature coils, two or more adjustable
rollers for supporting the floating core and centralizing it relatively to the spaces
within the armature coils.
Ninth. In a dynamo-electric machine, substantially of the character described,
mechanism for driving the armature core, consisting of one or more suitably sup-
ported shafts, such shaft, or each of such shafts if there be more than one, being
provided with two wheels, the one engaging with the periphery of one of the
rotating magnet discs, and being driven thereby, and the other engaging with the
periphery of the armature core and imparting rotation thereto.

page_text: Tenth. In a dynamo-electric machine, substantially of the character described,
the mechanism for adjusting the rollers which support and centralize the armature
_core, consisting of the cradles S S provided with adjustable fulcrums upon which
they rock, and acting, upon one side of the said fulcrums, through the push-bars r²
upon the arnis r¹, and also acting upon the other sides of the said fulcrums upon
the feet Q q³, affixed to the boxes Q1 q', as and for the purposes set forth.
Eleventh. In a dynamo-electric machine, substantially of the character described,
the mechanism for equalizing the work of the rollers which support or drive the
armature core, consisting of the cradles S, S provided with adjustable fulcrums
upon which they rock, each cradle upon the inner side of its fulcrum, supporting
the box R¹ of the central roller R; the two cradles acting upon the outer sides of
their fulcrums to support the boxes Q¹ q¹ of the side rollers Qq, and the guides for
guiding the movements of the boxes Q R¹ and q' in paths converging toward the
centre of the armature.
In witness whereof I the said Henry Harris Lake have hereunto set my hand
and seal this Thirteenth day of March in the year of our Lord One thousand
eight hundred and eighty three.