Improvements in Electric Meters and Motors for Alternating Pulsating, or Intermittent Currents.
Year: 1897

page_text: Improvements in Electric Meters and Motors for Alternating
Pulsating, or Intermittent Currents.
I, GRANVILLE FREDERICK PACKARD, a citizen of the United States of America,
residing at Fort Wayne, in the County of Allen, in the State of Indiana, Electrical
Engineer, 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 :-
My invention relates to improvements in electric motors, and in meters for
measuring the energy consumed in alternating, pulsating, or intermittent electric
currents.
One object of my invention is to provide a simple, economical, efficient, and
reliable meter having the fewest possible number of parts for measuring automatically
the electric current or energy consumed in a system for the general distribution of
electricity for light, heat, and power without the employment of commutators,
mercury-contacts, or other current-rectifying devices.
My improved motor for alternating currents is based upon the principle of
eddy-current repulsion and operates as though a fluid substance was escaping from
the poles and beating upon the fan-blades, thereby producing rotation of the
arinature.
My improved meter comprises one or more electro-magnets in inductive relation to
a revoluble arinature, the exciting-coils being connected in the work-circuit, through
which passes the current to be measured, a rotatable metallic armature provided with
radially-arranged retarding-vanes and rotated by the repellent action of the
eddy-currents set up by the magnetic blast of the said electromagnets, and a
registering-train so connected with said armature as to indicate the number of ampere
hours of current consumed in the circuit to which the meter is applied.
The principal novel feature of my invention consists in the construction of my

page_text: improved armature, by which I obviate the necessity of providing a separate damping
or retarding device.
Referring now to the drawings, in which similar reference numerals indicate
corresponding parts throughout the several views, Figure 1 is a perspective view of
the preferred commercial form of my improved motor adapted for use as a meter,
mounted in a proper containing-case and showing the relative arrangement of the
operative parts. Figure 2 is a plan of my improved armature in inductive relation
to the adjacent poles of the electromagnets. Figure 3 is a view in elevation of the
same with the inducing coils removed and showing the arrangement of the
laminated cores within the horizontal slots of the arinature-vanes. Figure 4 is an
elevation showing a modified form of the armature, the vanes thereof being tilted,
for the purpose described. Figures 5, 6, 7 and 8 illustrate modified forms and
arrangements of my improvement. Figures and 10 are diagrammatic views of
the same.
The energizing field-coils 9 and 10 are connected in the main source of supply
feeding the lamps or motors whose consumption of energy it is desired to measure,
and traversing these coils are iron cores 7 and 8, respectively, Figs. 1 and 2,
which cores may be arranged at any desired angle to the axis of the containing-coil,
as seen in the drawings. The said cores 7 and 8 are identical in form,
dimensions and construction, and have their plates or lamince rigidly secured together
by proper rivets 12, Fig. 1, (preferably three in number for each core) or in
other suitable manner. The said cores are horizontally arranged and in
approximately parallel relation, Fig. 2; they have their outer ends fixed in a
clamp 5 by means of a proper holding-screw 18. The said clamp 5. is swivelled
on the thumb-screw 6, which is mounted in a proper vertical screw-threaded
opening in the lug 3, one of which is cast with, or fixed upon opposite sides of
the said case 1, Fig. 1, thus providing for a convenient lateral adjustment of
said cores.
The containing-case 1, of suitable material, preferably metal, may be of any proper
form and may have an upright extension adapted to contain the dial 4 and its
accompanying registering-train, as seen in Fig. 1. At or near the centre of the base
of said case is arranged a jewelled thumb-screw 13, adapted to form a proper bearing
for the pointed lower end of the upright shaft 14; it is seated upon a proper
lock-nut 15 and affords a means for vertically adjusting the said shaft. In the top of
said case 1 is properly secured a vertical screw 16, Fig. 1, having its lower end
centrally drilled to receive and form a suitable bearing for the pointed upper end of
said shaft 14. In these two bearings, arranged in vertical alignment, the said shaft 14
is revolubly mounted and connected with a train of wheels communicating motion to
a suitable counting mechanism. The armature, of aluminium or other good electric
conducting material, rigidly mounted upon the said shaft 14 and secured thereto by
a set-screw or in other proper manner, coincident with its axis and in proper inductive
relation to said magnetizing or energizing source, has a central hub 17 and plurality
of radial vanes 11, preferably provided midway between their upper and lower ends
with an open transverse slot 20, adapted to receive the inner projecting free ends of
the said cores 7 and 8, as shown in Figs. 1, 2 and 3. The said blades are preferably
though not necessarily integral with the said hub. As the resistance offered by the
air to the rotation of said vanes affords the required retardation, my improved
armature obviates the necessity for a separate retarding device.
While the form and relative arrangement of my improved motor is that shown in
Figs. 1, 2 and 3, it may be adapted for driving other mechanism than that shown or
be otherwise variously modified without departing from the spirit and scope of my
invention. For example, the said blades 11 may be arranged in a tilted or inclined
position upon the supporting hub or arms, as shown in Fig. 4 in such a manner that
the "impact" of the magnetic lines pro luces a slight lifting effect which tends to
diminish or overcome the inertia in starting minimum loads. The said armature-blades
may also be bent or curved in the direction of rotation to increase the windage or
damping effect in a well-understood manner, as seen in Fig. 9.

page_text: When it is desired to increase the torque or turning moment, two of my improved
armatures may be fixed in vertical alignment upon the said shaft 14, as shown in
Fig. 7, with their respective blades arranged, preferably out of vertical
alignment.
Another obvious modification is the arrangement of a plurality of magnets in series,
whose cores are approximately tangential to the are of rotation of the armature-blades,
as shown in Figs. 5 and 8 and diagrammatically in Fig. 9. It is obvious that the
torque will be practically in proportion to the number of magnets employed. When
a plurality of magnets are employed, said cores 7 and 8 may be arranged as shown in
Figs. 5 and 8, a plurality of cores in each coil and the said cores arranged tangentially
to the arc described by the blades of the rotary armature.
The operation of my improved meter above described is obvious and, briefly stated,
is as follows: The rotation of my improved armature is produced by eddy-current
repulsion, the magnetic field acting upon the blades thereof like an escaping fluid,
taking the same direction as that of the lines of force of the magnetic field in which
the said armature is arranged, as shown diagrammatically in the simplest form in
Fig. 10, in which the armature-blades are acted upon or "bombarded" by the lines of
force. This is true because the relation of the armature-blades to the adjacent poles
is such that a large portion of the magnetic flux is intercepted by said blades
successively in a very efficient manner, since, as shown, the planes of said blades are
nearly at right angles to the normal path of the magnetic flux. Thus the speed of
rotation of the said armature proportional to the amount of current in the
circuit.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is-
1. In an electric meter, the combination of a rotary armature provided with radial
vanes for the purpose specified the said armature being adapted to be rotated by the
mutually repellant action of the inducing and eddy-current fields, said inducing fields
being established by the adjacent poles of one or more electromagnets; an energizing
coil or coils forming the winding for and exciting said magnets when traversed by
alternating electric currents; and a registering train or indicating device actuated by
the movements of the armature, all substantially as described.
2. In an electric meter or motive device an energizing coil or coils or field of force.
in combination with a rotary armature provided with a plurality of radial vanes or
damping devices so arranged in inductive relation to said field as to be successively
repelled therefrom, and a counting or registering train connected with said
armature, all substantially as described.
3. The combination in an electric meter or motive device of one or more
rotatable armatures each having radial retarding-vanes upon which are brought to
bear the inducing field or fields of one or more electromagnets for the purpose
of generating eddy-currents upon and repelling said vanes, and a registering-train
or indicating device actuated by the movements of said armature, all substantially
as described.
4. In an electric meter or motive device a rotary armature arranged in inductive
relation to an energizing field of force as shown, and provided with a plurality
of radial retarding devices so arranged relative to said field as to have induced
upon their surfaces eddy or vortex currents whose field is opposed or repelled by
the inducing-field, thereby producing rotation.
5. In an alternating-electric-current meter, the combination of a rotary armature
having a series of radial damping or retarding vanes arranged in inductive relation to an
energizing field of force, as described; a main circuit coil or coils traversed by the
current to be measured and embracing a plurality of laminated cores, as shown, having
their inner ends approximately tangential to the are of rotation of said vanes whereby
the said armature will be rotated by the magnetic blast emanating therefrom and

page_text: threading the plane of said vanes; and a counting or indicating device connected
with and actuated by said armature, all substantially as described.
Deted this 26th day of May 1907
For the Applicant,
J. C. CHAPMAN,
70 Chancery Lane, London, W.C., Chartered Patent Agent.