Improvements in Electric Current Meters.
Year: 1895

page_text: Date of Application, 10th Aug., 1895-Accepted, 28th Mar., 1896
Improvements in Electric Current Meters.
We, CARL ERBEN Watch Maker and EMANUEL BERGMANN, Merchant both
of Jerusalemerstrasse 48/49 Berlin S. W. in the Empire of Germany 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 :-
The present invention relates to improvements in that class of electric current
meters in which the amount of current that has passed through the meter in a
given time is indicated by the difference in indications between a normal clock and
one of which the rate of movement is influenced by the current through mechanism
directly or indirectly connected with the escapemeut balance spring or other
governing body of the said clock.
The improved construction for this purpose is illustrated in the annexed drawings
in which Fig. 1 is a front view and Fig. 2 a longitudinal section of one form of
construction of the improved electric meter, Fig. 3 a plan of details thereof.
The fixed coils e e are traversed by the current to be measured and tend to turn
through a larger or smaller angle the tension solenoids or magnetic bodies ii which
are solidly attached to the axle o.
The latter is adapted to revolve together with the solenoids ii in the bearings e¹ e*.
The two spiral springs which serve to offer a corresponding counter force
against the electro-magnetic effect with their inner ends insulated, are. secured on
to the shell 6 and with their outer ends connected by means of the arms u¹ u²
respectively with the arm b that is carried by, but electrically insulated from, the
axle o.
The springs v v³ serve at the same time to supply current to the coila i .
There is also keyed to the coil axle o a solid crank arm which is forked at its
lower end and connected by means of a crank pin with the arm attached to the
axle o so that the axle of follows the turning movements of the axle o. The
connection of the two crank arms has also for its object the regulation at will of
the relative position of the axle o and therewith the relative position of the axis of
of the coils ii attached thereto with regard to the axis of the (current) coils e e.
To the axle o' is further secured a suitably formed lever m which, following the
coils i according to the intensity of the current, revolves through a greater or
less angle. In the upper fork-like end of the lever m are the bearings for a smaller
axle o while its lower end is provided with a counter weight.c. To the axle of is
attached an angular piece p, the latter being at one end attached to the outer end
of a spiral spring the inner end of which is fastened to a projection m¹ of the,
lever m.
The other end of the angular piece terminates in a curved slotted arm
or fork c which therefore has movement about the axle of its direction being
determined by the spring f. The wheel train,,, r, of the clock to be
governed by and form part of this meter being actuated by a spring or a weight,
is regulated in its speed by a regulator.
2
This is effected by the pins attached eccentrically to the balance wheel u
moving to and fro the fork g which is rotarily mounted on the axle a' thereby
causing the anchor connected with said fork and also mounted on the axle a' to
operate in the usual manner with regard to the escapement wheel r¹.
c
In the working of this apparatus the electric bodies (coils, magnets) need not
swing with the clock work, as has been heretofore the case since the movable coils

page_text: or magnets ii adjusting themselves under the magnetic effect of the current coils e e
are independent from the clock work itself.
On the balance wheel' axle a' there is secured in addition to the balance wheel u
the inner end of a spiral spring 71 (Figs. 1 and 3). The outer end of the latter
is held by the arm of a two arnied lever q which is mounted on the axle a. The
other free arm of this lever q therefore follows the oscillation of the outer end of
spring and moves within the fork c; this said fork c as above described which is
mounted on the axle o' and held by the spiral spring f is therefore when the
clockwork operates moved to and fro through a larger or smaller angle by the
lever q.
The arcs of movement described by the lever q and of the guide fork c connected
with it, may be seen from Fig. 1. The guide fork c which serves as a damper,
being movably attached as aforesaid to the lever m and the position of the latter
on account of the above described mode of connection of its axle of with the coil
axle o depending on the position of the coils ii, thus the axle o of the fork c
according to the intensity of the current and the turning of the coils caused
thereby, is caused to assume different positions more or less near to the axis of
lever q.
"
According to the intensity of the current therefore the lever swinging with the
outer end of the spring f' occupies different places within the fork c. In consequence
according to the varying distance of the point of engagement of lever o from the
axis of rotation o, the moderating counterforce exerted on the spring is a
variable one according to the strength of the current passing at the time, and as
the end of the spring is exposed to a varying strength of resistance, the speed
of movement of the clock work therefore is varied according to the intensity of
the current, and the clockwork gains or loses time equivalent to the amount of
current that has passed.
Moreover arrangement has been made in the present electro-meter that the
prevailing intensity of the current or energy may be read from a scale d. For this
purpose there is attached to the lever m which alters its position with the coils į į
a small fork y adapted to engage with the pin n and thus force it to follow its
movements to all angular positions. Said pin is secured to an arm w which may
be turned about the axle o its other extrenity being fastened onto the outer end
of a spiral spring f which latter is mounted with its inner end on the axle o*
On to the latter is further attached a balanced hand; which having thus connection
with the lever m and following the displacement of the coils i i moves along the
scaled thereby indicating the intensity of the current or the electric energy
prevailing at the moment of inspection.
From the construction described it may be seen that the coils (or magnets) i i
being arranged entirely independently of the working of the clock, need not
follow the oscillation of the balance wheel u, but that they, by their different
position which corresponds with the intensity of the current, exert their influence
on the working of the clock by means of lever mechanism and an intermediate
regulating or moderating spring.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
:-
1. An electric meter in which fixed coils traversed by the current to be measured
influence the oscillation of a balance spring, and therewith the working of a clock
by giving to the oscillations of said balance spring a variable resistance or play,
the balance spring being directly or indirectly connected with a second spring by
means of a lever arm the effective length of which is regulated with the aid of
oils or magnets moved by the current to be measured for the purpose of taking
advantage of the gain or loss of time by the clock as a measure of the electricity
that has passed through the meter.
1
2. A form of construction of the electric meter described, wherein the position

page_text: of the coils or magnets caused by the current to be measured is indicated by an
index or the like for the purpose off reading off the intensity of the current_
prevailing at the time of the reading.
Dated this 10th of August 1895.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C., Agents to Applicants..