Electric Meters.
Year: 1893

page_text: Date of Application, 9th May, 1893-Accepted, 2nd Sept., 1893
COMPLETE SPECIFICATION.
Electric Meters.
I, OSCAR ERICSSON, a citizen of the United States, residing at Sioux Falls, in
the County of Minnehaha, and State of South Dakota, Electrician, 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:
This invention relates to electric meters, the primary object of which is to
provide a simple and accurate meter for registering the consumption of current in
what is known as the three wire system. The meter is also adapted for simple two
wire circuits.
Meters have been devised heretofore for registering the current of three wire
systems, but as constructed they have been more or less incorrect, especially where
there is a wide difference in the load of the two sides of the system. My invention
is designed to register the entire consumption, whether it be large or small and
whether the difference of load on the two sides of the system is large or small.
The details of the invention are an improvement upon the meter described in my
Patent No. 475,759, granted May 31, 1892.
The invention consists of the construction which will hereinafter be described
and claimed.
In the accompanying drawing,
Figs. 1 and 2 represent views of two opposite sides of the meter, the inclosing
case being removed; and
Fig. 3 represents an end view of the meter, the upper portion of the clock-work
or motor being removed.
Referring to the drawing by letter, A represents a base upon which the
apparatus is mounted, and A, A, two standards thereupon connected near the top
by a cross-plate A³. To the cross-plate is secured a frame B of a clock-work, the.
wheels and shaft of which are of the ordinary nature and therefore are not shown
in detail. One of the shafts 6 however, which preferably makes one revolution
per minute, projects through the sides of the clock-work frame and carries upon
each end a cam b¹, b², respectively. These cams are alike and are constructed so
that anything loosely resting upon their peripheries will be caused to gradually
move out from the shaft to the extreme throw of the cam and then quickly descend
to the lowest point of the cam next to the shaft. The clock frame also supports a
shaft 63 which, however, has no connection with the clock train. This shaft also
projects at both ends to the outside and carries at each end loosely adjusted
wheels 6, 6, respectively. These wheels are locked to the shaft by means of
cranks 66, 6, attached thereto, having pins b', 6' projecting into holes in one of
spokes of the wheel, as shown. These holes are a trifle larger than the pins so that
there may be a slight play of the wheels independent of the shaft. A bifurcated
lever 68 embraces each wheel and is pivoted upon the shaft. In the head of each
of these levers is pivoted a pawl 6, the toe of which bears against the smooth
periphery of the wheel. The outer end of the pawl on one side of the meter is
extended to form an arm 610; the outer end of the pawl on the other side of the
meter is very short but connects with one end of a vertical link 6", the other end
of which connects with a pivoted lever 6, as shown. Shaft 6 also carries a brake
disk 613 against which pawl 6" bears in the usual manner to prevent backward
movement of the shaft. In one of the standards A' a cross-stud c projecting in
both directions past the clock frame, is secured. Upon each end of this stud is
pivoted a long curved lever c', c², respectively, near the middle of which there is a
slot in which pins and ce connected respectively with the outer end of the

page_text: :
arm 60 and the lever-61, play. The lower edge of these arms c¹; ²; along the
outer half is curved downward for a purpose which will hereinafter appear.
D represents the frame in which the gear of the counting mechanism is mounted.
This with the dials is shown in dotted lines in Fig. 1. The first shaft of the train
projects through the back and carries a crank dengaging with a crank d¹ on one
end of the shaft 63, so that the motion of said shaft 6 is imparted to the counting
mechanism.
Directly upon the base of the meter and underneath the clock work are supported
two coils E; F, respectively, through which the current to be measured flows. In
the open center of these coils, shafts e, f, respectively, are mounted. The rotation
of these shafts in one direction is resisted by the usual coil spring e', and the
shaft carries an armature shown in Fig. 2 and pointers or current indicating
arms g, y¹, respectively. These coils with their connections, therefore, are ordinary
ammeters and may be substituted by any other form of ammeter known in the art.
The outer ends of the indicating arms 9, g' have cross-heads which stand directly
underneath the curved edge of the arms c¹, c³ respectively, and said arms are
adapted to rest upon the ends of the indicating arms for a purpose which will
hereinafter appear.
The curvature of the arms c¹, c² is such, that when the indicators g, glare at the
lowest or zero point, the arms are held at the highest elevation, and when the
indicators are at the position of full load, the arms may fall to the lowest point..
Having now described the construction, the operation is as follows: When the
meter is used to register the consumption of current in a three wire system, the
ammeter coils are connected respectively in series with the side wires of the system
and each is energized by the current flowing in the wire with which it is connected;
consequently the indicating arms will assume angular positions corresponding with
the current flowing in the respective sides of the system. The clock is supposed to
run continuously, and when no current is on, the indicators are at their lowest point
indicated on the drawing by a zero mark. Now when a load is thrown on, the
indicating arms have a tendency to move but cannot do so until the highest points
of the cams come around and lift the arms; then the indicators will move to a
position in accordance with the load. Owing to the slight play which wheels
and 6° have upon the counting shaft, the wheels are permitted to turn slightly and
the arms c', to rise slightly without imparting motion to the counting mechanism,
so that while the indicators are at zero, the cams rotate and simply raise the arms
a little without moving the counter every time the bighest points of the cams pass
under pius c and cª. This raising of the arms also frees the indicators, so, that if
current is flowing they may assume the proper position to indicate the fact, and it
will be observed they do this without the slightest resistance. I have therefore
overcome the fault in some of the present meters of failure to record the slightest
loads, and the fault in others of adding to the record when no current is flowing.
When the highest points of the cams have passed the pins c and c, the arms fall
until arrested by the indicators in their new positions.
•
Now in the next revolution of the cams as the arm c¹ is travelling upward, it
causes the wheel 6' and the shaft 63 to rotate, by reason of the engagement of the
pawl b, and therefore imparts motion to the counting mechanism in proportion to
the distance travelled and to the current flowing in coil E as indicated by g. But
as the arm c² is moving upward, the pawl 69 which it controls through lever ¹ and
link 6" is assuming a lower position on the periphery of wheel 6, without imparting
motion to the wheel. When the arms c¹ and c fall from the highest point of the
cam on to the ends of the indicators, the reverse of this operation takes place, i.e.,
the arm c¹ gives a new position to the pawl which it controls, while the arm c³
causes its pawl to grip the wheel 6 and turn it, thereby moving the counting
mechanism in proportion to the current flowing in coil F. as determined by
indicator g'. It will therefore be observed, that once in every minute the current
flowing in each side of the system is registered successively on the same counting
mechanism and that the total consumption is thereby measured.

page_text: It is understood, of course, that the cams may rotate once in two minutes or in
any desired period without departing from the spirit of my invention; also that
any form of motor may be substituted for the clock work herein described; the
only essential point being that the cams shall be rotated at a regular predetermined
speed. It is also to be understood that the clock work may be used to close the
circuit at regular intervals of a separate motor which in turn would rotate
the cams.
Although I have described two meters acting upon a single counting mechanism,
it is obvious that inasmuch as they record entirely independent of each other,
either one of them may be in operation without the other and equally as good
results obtained.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In an electric measuring apparatus, the combination of a plurality of separate
meters adapted to measure the current in a plurality of separate circuits of a single
counting mechanism registering the sum of the current flowing through all of the
meters.
2. In an electric measuring apparatus, the combination of a plurality of separate
meters measuring the current in separate respective circuits, of a single counting
mechanism registering the sum of the current flowing through all the meters, the
meters acting upon the counting mechanism in succession, substantially as
described.
3. In an electric measuring apparatus, the combination of two separate meters
adapted to measure the current in separate circuits, a single counting mechanism, a
shaft geared to said counting mechanism, two wheels on said shaft, two systems of
levers for imparting a step by step movement to the wheels, and a motor adapted
to move said systems of levers, said meters determining the extent of the movement
which the motor shall impart to the systems of levers, substantially as described.
4. In an electric measuring apparatus, the combination of a counting mechanism,
mechanical devices through which motion is imparted to the counting mechanism, a
motor moving said mechanical devices periodically, and a current indicator
determining the distance which the motor shall move the counters, lost motion
being allowed in said mechanical devices whereby they may move a slight distance
before the counter is affected.
5. In an electric measuring apparatus, the combination of a motor, a shaft
rotated thereby, two cams on said shaft, two systems of levers moved respectively
by said cams, a counting mechanism, a driving shaft for the same, two wheels on
the driving shaft, said wheels rotated respectively by said systems of levers, and
two current indicators determining the distance which said levers shall be moved
by the cams.
Dated this 8th day of Max 1802
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent.