Improvements in Electric Motors and Generators.
Year: 1886

page_text: Improvements in Electric Motors and Generators.
We ENOS TOLAND HIGHAM and DANIEL HIGHAM both of N° 2165 East
Cumberland Street in the City of Philadelphia State of Pennsylvania United
States of America, Lumber Merchants, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Our Invention consists of certain improvements in the construction of Electro
magnetic motors and electric generators designed with the view of increasing their
efficiency as more fully described hereafter.
In the accompanying drawings:
Figure 1 is a side view of an electric motor embodying our improvements.
Figure 2 is a transverse section on the line 1-2 Figure 1 but with the armature
removed.
Figure 3 is a detached view of the armature partly in section.
Figure 4 is a perspective diagram illustrating the construction and operation of
our preferred form of commutating device.
Figure 5 is a diagram illustrating the manner of winding the coils and
Figure 6 is a diagram of a modification.
In these drawings we have illustrated our improvements as applied to a Motor
in which the armature has three poles revolving between the two opposite poles
of the field magnets but it should be understood that our improvements are
applicable to different constructions of electric motors and also to dynamo electric
machines or electric Generators.
In the construction of Motor shewn in Figure 1, E and E¹ are the Electro
Magnets with pole pieces e e¹ between which the armature A revolves.
To the back ends of the Field Magnets are secured the curved connecting
plates B, B1 united by central cross bars D on opposite sides, these central cross
bars being provided with bearings for the axis A¹ of the armature.
In winding the coils of the Field Magnet and armature we prefer in order to get
the largest number of coils with the necessary conducting surface within the
smallest space to wind in between the usual coarse wire coils x (Figure 5), coils of
Dino R71

page_text: fine wire y-the terminals of which are electrically connected to the coarse wire
coils so that the two kinds of wire are wound on the same core in parallel circuits
and connected together at their terminals.
We prefer to slot the pole pieces of the armature as shewn in Figure 1 with the
view of breaking up or preventing the formation of interfering magnetic currents
and for the same reason we prefer to divide the core and pole pieces of each electro
magnet into two parts on a horizontal line and to insulate the two parts from each
other. We do this however for a further reason which we will explain.
It will be observed in figure 1 that the curved pole piece of each field magnet is
of such a length with relation to the poles of the armature that two of the poles of
the armature will be within the field of one magnet at the same time, these two
poles of the armature being north and south so that if the pole of the field were in
one continuous piece it would to a certain extent form a connecting piece for the
two poles of the armature and thus retard the action of the machine, but by
introducing the strip of insulation at f as described, this is avoided and the machine
works to a much greater. advantage.
One of the features of our Invention consists in making the cross bars D and
the armature shaft A' as well as the connecting plates B, B1, of magnetic metal so
as to form a complete magnetic circuit from the upper part of the pole E for
instance through the connecting portion of the plate B cross bar D shaft of the
armature and core and pole piece of the coil I so as to increase the magnetic action
between the poles of the field and armature.
The cross bar D particularly forms a neutral part of the magnetic circuit of the
the field just as the armature shaft constitutes practically the neutral part of the
magnetic portion of the armnature, and the cross bars D bear such relation to
the armature coils, that as the armature coils pass the bars D, the electric currents
travelling in the said coils will generate in the bars D magnetic currents which
will be in a direction that will augment the magnetic currents set up in the
attracting poles of the field.
Another important feature of our Invention relates to the commutating of the
currents in the armature one of the objects of our Invention being to dispense
with the brushes and segments almost universally used in Electric motors and
Dynamo electric machines for it is well known that these are the parts of the
machine which give the greatest trouble. and are the most difficult to keep in order
and repair.
For this purpose we replace the mechanical commutator by an electro-magnetic
commutator the construction of which will vary somewhat with the construction.
of the machine and its requirements, but in the drawings we have illustrated the
form of magnetic commutator which we prefer to use-With this construction of
magnetic commutator the entire metallic portion of the machine in both the field
and the armature and its shaft is divided vertically into two parts insulated from
each other either by air or other means. This will be understood on reference to
figures 2 and 3 the poles of the field in Figure 2 being shewn as divided by the
vertical insulating plate g while there is a corresponding insulation h for the two
parts of each pole of the armature and armature shaft.
It is not essential however that this insulation should be central or that the
metallic portion of the field should be divided as shewn so long as the bearing for
the armature shaft on one side is insulated from the bearing for the armature
shaft on the other side.
.
•
In the construction of the machine shewn, there being three poles to the
armature, there are three sets of commutating devices each set consisting of a
permanent magnet a (or a¹ a²) pivotted to an insulated radial post p carried by
the armature shaft, the opposite ends of the permanent magnet being north and
south of course.
The pivoting point of the permanent magnet is central so as to get as perfect a
balance as possible.

page_text: These permanent magnets a a¹ a² are preferably parallel with the armature
shaft A', and projecting radially from the shaft are the contact points 1, 11, 2, 21,
8, 31, in pairs corresponding with and parallel to the several posts p. pl p².
The lengths of these pairs of contact points are such as to allow a slight tilting
motion to each of the balanced magnets a a' a' so that these magnets may make
contact through one or the other of their ends with one or other of their contact
posts.
It will be seen then that as the armature revolves, when one of the balanced
magnets comes within the field of one of the poles of the field Magnet, say the
north pole, the south pole of the balanced magnet a³ for instance (Figure 4) will
be attracted and the opposite end or north pole of this balanced magnet will be
thrown into contact with its post 3, while the opposite end is thrown out of
contact with the posts 31.
The manner of connecting up the coils of the armature to these commutating
devices above described is not a very material part of our Invention as they may
be connected in different ways as may be desired but in the diagram Figure 4 we
have shewn the opposite terminals of each intermediate coil connected to the
adjoining posts p, p¹ p* Thus one terminal of the coil I is connected to the
post p while the other terminal is connected to the post p, and to the latter is
connected also one terminal of the coil II while the other terminal of this same
coil II is connected to the post p¹ and the terminals of the coil III are connected
to the posts p¹ p as indicated.
The field circuit is illustrated in Figures 1 and 2. The current entering the
post q passes through the coil of the core E and is thence conducted to the cross
piece 1) and to the portion of the armature shaft A having its bearings therein.
It then passes to the armature coils and out at the other insulated end of the
armature shaft A¹. The current thence goes through the bearing of the said shaft
in the cross piece D¹ to the coil of the magnet E and out at q¹ the circuit being
such, as will be seen, that the armature is in series between the coils of the field.
Take an example armature circuit, when the armature is in the position shewn
in Figures 1 and the current will be entering through the contact post 1.
(Figure 4) balanced magnet a and through the post p where the current will split
one half going through the coil I and the other half through the coil II whence
the two portions of the current may pass to the posts p¹ ps and out through the
balanced magnets a¹ a² and contact posts 21 31-The coil III will thus be out
of circuit at the moment when it is in a position (figure 1) to be of little or
no use.
In order to preserve the magnetism of the Magnets a a¹ a² we prefer to place
coils m m² as shewn in Figure 3 around the legs thereof to both of which coils the
terminals of the adjacent armature coils are connected (instead of to the post as
described above with reference to the diagram Figure 4) the opposite terminal of
the coil m or m¹ being connected to the platinum point which is to make contact
with the post 1 1° & as the case may be.
The direction of each coil m m³ is such as to maintain the desired inagnetism
and polarity of the balanced levers a a¹ a³.
It will be understood that instead of mounting the reversing bars and conductors
or magnetic commutating devices within the field poles they may be arranged to
rotate with the armature outside the field and be acted on by north and south poles
of either an electro magnet or permanent magnet specially provided. For instance
in Figure 6 we have shown the magnetic commutator as mounted on an extension
of the armature shaft outside the frame of the motor and adapted to be acted on
by poles N' S¹ of a separate permanent magnet or magnets.
In reversing the motor by changing the connections of the line Conductors at
the binding posts q q¹ (Figure 1) where a permanently Magnetic Commutator
is used it will be observed that the result will be to reverse the fields only and
not the armature, as in motors of the usual construction. This is one of the
advantageous features of our Invention.
·

page_text: Having now particularly described and ascertained the nature of the said
Invention and the manner the same is to be performed I declare that what
I claim is
First. An electric motor provided with an armature and a magnetic Comutator
carried by the armature.
Second. An electric motor provided with a rotary armature carrying an automatic
magnetic commutator and poles to act thereon as the armature revolves.
Third. An electric motor having automatic magnetic reversing bars adapted to
rotate with the armature, magnetic poles to act on said bars and contact points with
which the armature terminals communicate substantially as specified.
Fourth. An electric motor having pivoted and balanced magnetic reversing bars
adapted to rotate with the armature, magnetic poles to act on said bars and
contact points with which the armature terminals communicato substantially as
described.
Fifth. An Electric motor having automatic magnetic reversing bars provided
with coils adapted to be thrown into circuit: as the bars operate to maintain the
magnetism of the bars substantially as and for the purpose set forth.
Sixth. The combination of the armature shaft in two parts insulated from each
other and field magnet frame having the bearings for the shaft insulated from each
other with magnetic reversing bars and contact points therefor carried by the two
parts of said shaft substantially as set forth.
Seventh. The combination of the armature shaft in two parts insulated from
each other and field magnet frame having the bearings for the shaft insulated from
each other with magnetic reversing bars and contact points therefor carried by the
two parts of the shaft the terminals of the armature coils being connected to
the magnetic reversing bars as and for the purpose described.
Eighth. An electric motor having an armature, magnetic reversing bars to which
the terminal coils are connected and carried by the armature, and contacts to which
the field terminals are connected as set forth.
Ninth. An electric motor or dynamo electric machine having its electric magnets
wound with fine and coarso wire coils on the same cores with their terminals
directly connected to each other in parallel circuit.
Tenth. An electric motor having each field pole piece adapted to extend over
the north and south poles of the Armature the two parts of the Field pole adjacent
to the two armature poles being magnetically insulated from each other.
Eleventh. An electric Motor having its field pole pieces and cores in parts
insulated from each other at f as described.
Twelfth. An electric motor having its pole pieces and cores in parts magnetically
insulatod at but each polo magnetically connected to the opposite one through
the frame.
Thirteenth. An Electric motor having a rotary arinature with its poles magnetically
connected with the poles of the Field through the Frame substantially as set forth.
Fourteenth. An Electric motor baving bars D crossing the coils of the armature
and connected magnetically to the neutral parts of the field magnets for the purpose
Bet forth.