Improvements in Apparatus for Recording Electric Currents.
Year: 1893

page_text: Date of Application, 1st Dec., 1893
Complete Specification Left, 31st Aug., 1894-Accepted, 13th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Recording Electric Currents.
1, HERMANN ARON, of 6 Lützowstrasse Berlin, in the Kingdom of Prussia,
German Empire, Doctor of Philosophy and Professor, do hereby declare the
nature of this invention to be as follows:-
11
My invention relates to that class of apparatus in which the amount of electrical
current is measured by the deviations of two clock-works or wheel-trains, one
of which is accelerated or retarded in its normal speed by the influence of the
current.
The object of my present invention is to avoid the incorrectness of the records
which arise from irregularity in the normal speed of either of the two clock-works,
caused by deficient regulation of the same.
In apparatus of the class referred to, the true regulation of the two clock- or
wheel-works is of great importance. Small deviations in the normal speed of the
two works are unavoidable; as long as the consumption of current is considerable,
such deviations are but of little account, but, during the time where no or but little
current is being delivered, they enter into account, as they become gradually added
to or subtracted from the record already obtained. And even if the two clock- or
wheel-works are stopped during the time where no current is delivered, such
deviations in the normal speed of the two works cause the records to be deficient
and failing in their desired exactness.
The deficiencies hitherto existing in apparatus of the class referred to are
overcome by the improvements of my present invention, which consists in alternately
reversing the motion of the apparatus, while, at the same time, the flow of the
current to be measured is caused to change its polarity. By this means, but one
reversing motion is required for compensating the irregularities of the normal
speed, while for the current two reversals are obtained; these two reversals
counteract each other, and consequently the index which records the amount of
current delivered moves only in one direction, while the deviations in the normal
speed of the two clock-works are eliminated from the record by the reversal of the
motion of the apparatus.
To make my invention more fully understood, I hereinafter describe one
modification of apparatus by which the object in view may be obtained.
The measuring parts of the apparatus are, in certain intervals, reversed, by means of
a shaft, as will be further described, the said measuring parts, accordingly, will deviate
in a different direction during the alternating periods. On the said shaft is
mounted an eccentric, which, engaging with the fork of a forked arm suitably
pivotted, shifts the latter into either of its extreme positions, to the left or right.
At the end of each interval or period, the shaft and eccentric suddenly make one
half of a revolution and thereby shift the fork into its other extreme position.
The said forked arm is pivotted between two bars or stays, which carry three
toothed wheels in gear with each other; the central one of which wheels carries
the first finger of the recording dials. The axis of said central wheel is in line
with the pivot of the forked arm, but the said axis and pivot are independent of
each other.
On the axis of the differential work which records the deviations of the two
clock-works, I place a toothed wheel in gear with a similar wheel. According to
the alternating position of the forked arm, the wheel to the left of the central wheel
will be brought into gear with the wheel of the differential work, or the wheel to
the right of the central wheel will be brought into gear with the wheel to the right
of the differential wheel. Now, if the differential-counter, owing to insufficient
ri

page_text: .
regulation of one or both of the clock-works, deviates in one direction, while the
left wheel of the train of three is in gear with the differential wheel, the recording
index will deviate in the same direction. After a determined period or interval,
the forked arm is shifted to its other extreme position, and thereby the right wheel
of the three enters into gear with the second differential wheel, and, turning with
same, brings the index back to its former position..
During the time when current is delivered, the index on the axis of the
differential wheel moves in such a direction that the consumption of current is
recorded, in addition to the undue deviations in the normal speed of the two clock-
works. Now, as the fork is being shifted, the measuring wheel train is reversed in
such a manner that the two clock-works deviate proportionately to the expense of
current, less the amount of deviation caused by the undue difference of the normal
speeds. The shifting of the fork as described has brought the right wheel of the
train of three in gear with the second differential wheel, and thereby the changed
direction of the differential work will cause the recording index to move on in the
same direction as before. It will be understood, then, that the deviation of the
two clock-works, which is caused by irregularities in their normal speed, turns
the recording index in different directions, whereby each second period compensates
the deviations of the previous period, while those deviations which are caused
by the delivery of current, move the said index constantly forward in the same
direction.
The mechanism which operates the reversing motion of the shaft and eccentric
consists, according to one modification of my invention, of a toothed wheel, loosely
mounted on an axis and receiving rotary motion from any convenient moving part
of the apparatus. On the same axis, a disc or wheel is fixed, having a projecting
pin or stud, which bears against the bent end of a pivotted arm. The said disc is
connected to the toothed wheel by a spiral spring. As long as the stud is in
bearing contact with the said arm, the disc is prevented from turning, and,
accordingly, the spring is wound up as the toothed wheel revolves. When the
said wheel has moved on sufficiently and the spring has acquired sufficient tension,
a pin or stud projecting from the said wheel strikes against an inclined face of the
pivotted arm, whereby the latter is swung on its pivot and the bent end comes free
from the pin of the disc. The disc, under the driving force of the spring, now
turns until its pin strikes against another arm, which extends from and is integral
with the beforenamed arm; these two arms meeting at the pivot form a V-shape.
This second arm is also provided with a bent end and inclined face, both of which
are opposite to those on the other arm, but rather different in shape. When, after
another half revolution of the toothed wheel, the pin of the latter strikes against
the inclined face, the second arm, in its turn, is swung back, and its bent end moves
out of the path of the disc pin, and the disc turns on till its pin is once more stopped
by the first named arm.
On the shaft of the toothed wheel, there is further mounted a commutator of any
known construction, destined to reverse the direction of the current in one half of
the measuring part of the apparatus. When used for a Coulomb-meter, the
commutator has two conducting rings against which brushes have a sliding contact,
the said brushes being connected to the ends of a resistance. The said rings are
provided with conducting extensions against which the brushes alternately slide,
while the said commutator is turning, the current, thereby, is reversed in the coil
above which swings a magnet attached to the pendulum of one of the clock-works,
as known in that class of measuring apparatus. The coil is connected in a shunt
circuit to the resistance to avoid its being passed by too strong a current.
In a Watt-meter, the commutator reverses the direction of the current in the
tension-conductor, in shunt to the working line.
Dated this 30th day of November 1902
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.

page_text: Improvements in Apparatus for Recording Electric Currents:
I, HERMANN ARON of No. 6 Lützowstrasse, Berlin in the Kingdom of Prussia,
German Empire, Dr. Philos. and Professor, 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 that class of apparatus for recording electric currents, in
which the amount of current delivered is measured by the deviations of two clock-
works or wheel-trains, one of which is accelerated or retarded in its normal speed
by the influence of the current to be measured. The object of my present invention
is to avoid the incorrectness of the records which arises from irregularities in the
normal speed of either of the two clock-works caused by deficient regulation of
the same.
In apparatus of the class referred to, the true regulation of the two clock-works
or wheel-trains is of great importance. Small deviations in the normal speed of the
two works are unavoidable. As long as the consumption of current is considerable,
such deviations, not caused by the current, are but of little account, but during the
time where no current, or but very little, is being delivered, they do enter into
account, as they become gradually added to or subtracted from the record already
obtained. And even if the two clock-works or wheel-trains are stopped during the
time where no current is delivered, such deviations in the normal speed of the two
works cause the records to be deficient in stating the exact amount of current
delivered.
The want of exactness hitherto existing in apparatus of the class referred to is
overcome by the improvements of my present invention, which consists in alter-
nately reversing the direction of motion of the counting or recording train, whilst,
at the same time, the influence of the current to be measured is caused to change
its polarity. By this means, but one reversing motion is required for compensating
the irregularities of the normal speed, while for the current, two reversals are
obtained; these two reversals counteract each other, and consequently, the index
which records the amount of current delivered, moves only in one direction, while
the deviations in the normal speed of the two clock-works or wheel-trains are
eliminated from the record by the reversal of motion.
In other words, I cause the recording index to alternately count forward and
backward, that is, the electric current to be measured is caused to operate its
influence on one of the two works alternately by accelerating the speed and by
retarding the same. During the period of acceleration, the undue deviation of the
two clock-works is added to the amount of deviation caused by the current, and
during the period of retardation, the said undue deviation is subtracted from the
record of current delivered. The said undue deviation, accordingly, is eliminated
from the result. It will only be necessary to provide mechanical means which,
during the latter period referred to, will cause the recording train to rotate in the
same direction as during the former period. Without such means, the recording
train would, during the period of retardation, move in the direction contrary to
that in which it moves during the period of acceleration. But by the change
operated in the direction of the recording train, the deviations of the two works
during the two alternating periods, that is, the deviations by acceleration and those
by retarding the speed, are added to each other, while those deviations resulting
from difference in the normal speed of the two works, which I call undue deviations,
are added in the first period and then subtracted in the second period, and
consequently obliterated in the final record.
Owing to this improvement, a degree of exactness of the records of the
instrument is obtained which hitherto stands unparalleled.

page_text: In order to make my invention more fully understood, I shall hereinafter describe
the same with reference to the accompanying drawings, in which I have illustrated
several modifications of mechanical means by which the object in view may be
attained.
In the modification shown in Figure 1, a is a shaft through which the
measuring parts of the apparatus are, in determined intervals, reversed, as will be
further described, the said measuring parts, accordingly, will deviate in different
directions during the two alternating periods. On the said shaft a is mounted an
eccentric d, by means of which a forked arm e is moved into either of its extreme
positions to the right and to the left; the latter one is shown in Figure 1. At the
end of each period, the said shaft a receives a sudden impulse, causing it to make
one half revolution, whereby the eccentric d shifts the forked arm into its opposite
position. The arm f of said fork e is loosely mounted on a shaft c, carried by two
bars g, between which three toothed wheels h, i, k, in gear with each other, are
arranged to turn. The axis c of wheel i carries the first index of the recording
train. is the axis of the differential counter recording the difference of the two
clock-works or wheel-trains; on the said axis b is mounted a wheel Z lin
with
gear
another wheel m. According to the alternating position of the forked lever f, the
said wheel will be in gear with wheel h, or the wheel m with wheel k. Now, if
the differential-counter, owing to a deficient regulation of the clock-works, should
deviate in the direction of the arrow, the counting gear will deviate in the same
direction. After a determined interval, the lever ef will be reversed, whereby
the wheel m comes into gear with wheel k, which causes the axis i to turn in a
direction contrary to the axis b, and whereby the counting gear is returned to its
former position.
When the current is being delivered, wheel will deviate in the same direction,
as indicated by the arrow, and the counting gear will be advanced proportionately
to the amount of current delivered, additional to the undue deviation caused by
the deficient regulation of the clock-works. In the same moment when the forked
arm ef is being reversed, the measuring device is equally shifted, thereby causing
the two clock-works to deviate according to the amount of current delivered, but
less the amount of deviation caused by deficient regulation. By reversing the
position of the lever ef, the wheel m comes into gear with wheel k, as described,
and owing to this, the changed direction of the differential gear will cause the
recording gear to move on constantly in the same direction. It will be understood,
then, that the undue deviations of the clock-works cause the counting gear to move
in opposite directions during the two alternating periods, whereby, at the end of
cach double period, the same position is obtained from which the counting gear
started, while those deviations caused by the current delivered, reversing the
motion of the differential counter, cause the counting gear to move on constantly
in the same direction, thus recording the exact amount of current delivered.
The shaft a, besides the eccentric d, carries further a commutator of any known
construction, destined to reverse the direction of the current in one half of the
measuring parts.
Figure 3 is a general plan showing the connection of the commutator applied to a
Coulomb-counting apparatus. n is the commutator, carrying two sliding surfaces o,
of conducting material, against which surfaces o two brushes and p bear, said
brushes being connected to the ends of the resistance q. The said sliding rings o
are provided each with a rod, said rods making contact with either of the two
brushes sors", whereby the current in the main coil is commutated. Above the
said coil, a magnet is arranged to swing in a well known manner. The said coil t
is connected in a shunt circuit, to avoid great strength of current passing
through the commutator, which would require the same to be made of considerable
strength.
If applied to an apparatus for counting Watt-hours, the connection is made as
shown in Figure 4. The commutator is the same as shown in Figure 3, but
commutation is applied to the conductor of tension, in shunt to the lamps.

page_text: The mechanical device by which, at determined intervals, the shaft a is causedl
to make a sudden half revolution and by which both the counting gear and one
part of the measuring apparatus are simultaneously reversed, is illustrated by
Figure 2.
u, is a tooothed wheel receiving constant rotary motion by means of any suitable
driving device. On the axis of said wheel, a disc is loosely mounted, connected
to the wheel u, by a spring w. In its rotary motion the wheel, will carry the
disc r, along, till a stud a, carried by the said wheel u, will bear against an arm,
of a lever, pivoted as at A. By the said stopy, the disc e, is prevented from
following the rotation of wheel u, and, consequently, the spring w, is being wound
up. In the further rotation of wheel u, a stud B, projecting from the said wheel u,
will strike against an inclined surface provided on the lever, whereby the army,
of said lever is removed from the stop a. The tension of spring w, now suddenly
turns the disc v, until the stop a, strikes against the other end B', of the stud B.
Of course, the said stud B B³, must be so shaped that its end B', may freely pass
below the army of lever z. In moving further on, the arm 13 of wheel u, will slide
off the surface C of the lever, thereby allowing the said lever, and lever-arm y
to take its former position, blocking the path of the stud, and the play begins as
before.
The sudden revolution of the disc e, obtained as described by the spring w, is
communicated to the common shaft a, by means of gear-wheels D, and D', the gear
wheel D, being fixed to the disc e, and the wheel D, mounted on the shaft a. The
wheel D, has only half the diameter of wheel D¹, and, consequently, when D
mades a sudden full revolution, D¹ will only make one half turn.
The mode of working my improved apparatus will be better understood, still, if
explained by an example.
First. Suppose that no current is passing through the instrument. A difference
between the normal speed of the two clock-works exists, which, during one half of
the determined period advances the differential counter in the direction of the
arrow at 1, Figure 1, by the amount n. The eccentric d, takes the position, as
shown in Figure 1. Wheel is in gear with wheel h, and wheel in gear with
wheel the counting gear, driven by the axis c of wheel i, will, accordingly,
record the said deviatioun in the positive way, showing n
At the end of said half
period, the arm B, of wheel u will strike against the surface C of lever y, z, with-
drawing the arm y, from the stop e, whereby the disc e, is caused to make a sudden
revolution, and the eccentric d one half revolution. This changed position of the
cccentric d, throws the wheels k, and m, into gear, disconnecting the gear between 7.
and h, and, accordingly, the axis c, of wheel i, will turn in the reversed direction.
The second period is of the same length as the first period. The deviation of the
two clock-works, during this second period will be the same, as in the first period,
But as the direction of wheel, is now reversed, as compared with that
of the differential counter, the counting apparatus will record the deviation + n,
registered by the differential counter, as
(+1).
n, accordingly as
The sum of the records in the first and in the second half of a full period, there-
fore, will be " − 1 = σ, and, consequently, the deviation of the speed of the two
clock-works will not be recorded, nor is the former record of the instrument
changed by such deviations in the normal speed.
i.e., n.
-
-
=
11.
Second. Suppose that the delivery of current during one half of a full period
be Coulomb the deviation of the normal speed between the two clock-works,
as before, is during the same time. By the delivery of current the axis b, of the
differential-counter is turned by the amount + in the same direction as by the
undue deviation +n, i.e. in the direction of the arrow. During the first half of
the period, wheel 1, is in gear with wheel 1, and the brush pl, Figure 3 is in
conductive connection with brush s". Supposing the upper brush of the dynamo
to be connected to the positive pole of the armature, the current will flow through
the coil t, from high downwards. At the end of the said half period, the recording
index, driven by the shaft'c, has registered + + n. By this time the disc v

page_text: suddenly makes one revolution and, accordingly, the shaft a, is caused to make one
half revolution. This, as described, causes the wheels and 1, to be thrown out of
gear, and wheel enters into gear with wheel k through the medium of wheel m, at
the same time the conducting connection between brushes p' and 8" is broken and
connection made between brushes p' and s, and between p" and s. The current
will now pass from below upwards, taking the reverse way through the coil,
whereby the deviations of the clock-works caused by the current to be measured,
have the negative direction and the axis b, of the differential counter will turn in
the direction contrary to the arrow at 1, Figure 1. Accordingly, if the delivery of
current during the second half period be e', the shaft b, would be turned by the
amount of, if no undue deviation + did exist. This undue deviation makes
the record of shaft b, false, because the total deviation has not been
but - ε²¹² + n.
Now, as the records in every half period are false by the
amount of +1 or , the sum of both records of the two half periods will be
( + e + 1 + ɛ' − 11) =+, this being the exact amount of deviation caused
by the current to be measured, and the deviation by undue difference of speed
is entirely eliminated.
-
-
The length of each determined half period is so short, that the undue deviations
occurring during each half period, destined to balance each other, are equal to each
other or can differ but so little that any difference is of no account.
The described improvement, further offers the great advantage, that even if one
of the two clock-works or wheel-trains should happen to stop, the records already
obtained up to the moment remain unaltered, as the stopping of one clock-work
may be considered as a maximum of difference of speed between the two works,
said maximum being eliminated as well as small amounts of deviation, such as the
amount before mentioned.
Another advantage obtained is this, that the proportionality of the records is
increased almost to perfection. In Coulomb counting apparatus, the quadratic
member of the formula developed in the theory of the instrument is objectionable,
as it is difficult to eliminate the same, if the clock is made to go fast, it becomes
added to the records obtained in proportion to the energy of current delivered. In
the second half period, the said quadratic member becomes subtracted, and,
accordingly, it is entirely eliminated from the final record.
The mechanical means for reversing the motion of shaft c, carrying the recording
index, may be constructed in a variety of ways; the device shown in Figure 1 may
preferably be replaced by one of the following devices:
In Figure 5, a, is the shaft carrying the eccentric d, as in Figure 1, the forked
arme, being alternately thrown into two extreme positions by the said eccentric. On
the axis H, round which the forked arm e, is swinging, two levers e¹, el, are
mounted. The axis b, of the differential counter recording the deviations of the
two clock-works, extends to the front, and carries a cross-shaft I, with a planet-
wheel M, in gear with two crown-wheels and mounted loosely on the same
shaft b, and receiving motion through the said planet-wheel. The said planet-
wheel M, and crown-wheels,, in their combination form a kind of differential
gear, through the planet-wheel M, the two crown-wheels are driven in the same
direction. The crown-wheel is in gear with another crown-wheel, through an
intermediate wheel L, while the other crown-wheel 1, is meshing directly into a
crown-wheel. Between the two crown-wheels and ", a planet-wheel N,
placed, the cross-shaft of which is mounted on the axis c, which carries the crown-
wheels,, loosely mounted on it. The said crown-wheels, with their planet
wheel N forin another differential gear, the crown-wheels of which are turning in
opposite directions. If the two crown-wheels 1, 111, are turning with equal speed,
the planet-wheel N turns on its cross-shaft, but if either of the two crown-wheels
stops, the said planet-wheel N, will rotate round the axis c, in either direction, the
direction being determined by the crown-wheel which continues to move. According
to the position of the eccentric d, either the crown-wheel ', is stopped by the
lever e¹, or the crown-wheel ", by the lever e". The crown-wheel 1, being
is

page_text: stopped, will simultaneously stop the crown-wheel it, and the crown-wheel 7", being
stopped will stop the crown-wheel ". The two planet-wheels M, and N, will run
with equal speed. The cross-shaft of the planet-wheel N, while turning, drives the
axis e of the counting apparatus.
The mode of working this modification is as follows
At the beginning of the period the eccentric is supposed to keep the position
indicated by Figure 5, the crown-wheel , being stopped by lever e. Through
the influence of the current delivered, the axis b, is being turned in the direction of
the index of the clock. The crown-wheel ", is turned by the planet-wheel M, and
imparts motion to the crown-wheel ", which, in its turn, causes the planet-wheel N,
to turn the axis c, in the direction opposite to that of shaft b. At the end of the
half period, the eccentric is reversed, as described, whereby the lever el, stops the
crown-wheel, leaving the crown-wheel free to revolve. At the same time,
the current to be measured is so commutated, that the amount of current delivered
causes the shaft b, to rotate in the direction contrary to the index of the clock.
The shaft b, and planet-wheel M, accordingly, drive the intermediate wheel L, and
consequently the crown-wheel, in the same direction. It will be understood, then,
that the recording shaft c, which had been turned contrary to the direction of the
index of the clock during the first half period, continues the same direction in the
other half period, and, consequently, the deviations caused by the current delivered,
are registered in continuous succession, while the undue deviations caused by
insufficient regulation of the clocks, are eliminated in the same manner, as has been
explained with reference to the device of Figure 1.
The same results may, further, be obtained by the modification illustrated in
Figures 6 and 7, Figure 6 being a side elevation and Figure 7 a sectional plan.
As in the other modifications, Figure 1 and Figure 5, a is the shaft for reversing
motion and d, the eccentric upon said shaft, working within the fork e, of a lever,
pivoted as at c². Below its fulcrum c', the lever f, carries two pins H¹, H,
engaging in a groove of a sleeve K, on the shaft J. The said sleeve K, engages
with its shaft J, by a feather and groove, allowing a sliding motion in the
longitudinal direction, but preventing the sleeve from turning loosely on the shaft.
Each end of the sleeve K, carries a bevel-gear L', L", and the shaft J, has keyed
to it a bevel gear M', meshing with another bevel gear N, on the shaft b, of the
differential counter. The said shaft b imparts motion to the shaft J, by means of
the gear wheels M' N' and the rotary motion is transmitted to a bevel gear O,
either through the wheel L, or by the wheel L", as the sleeve K is shifted to
engage one or the other of said wheels with the said wheel O. If the shaft b,
would constantly turn in the same direction, the said wheel O, owing to the
alternating position of the eccentric d, and sleeve K, shifted by the pins H¹ H",
would alternately be driven in opposite directions. But owing to the circumstance
before described, that simultaneously with the reversal of the eccentric d, the
commutation of the current changes the direction of the shaft 6, the wheel O, will
continually be driven in the same direction. The axis c, of wheel C carries and
moves the recording train.
Figures 8 and 9 represent another modification of the device serving to obtain
the same result.
ȧ is the shaft carrying the commutator (not shown in the drawing) on the same
shaft is mounted a drum or cylinder Q having a cam groove in its circumference,
into which groove engage the two pins or studs of a forked lever R, pivoted as at S
and acting with its lower end against a ring T, engaging into a slot between the
forks U¹, U, which forks are so mounted on the shaft 6 of the differential counter
to allow of a longitudinal sliding motion on said shaft. The said forks U¹ U"
are connected by springs V₁ V On the same shaft bare mounted two gear
wheels WW", one of which meshes directly and the other through an intermediate
wheel with a gear wheel X on the shaft c of the recording train.
It will be easily understood that, according to the position of the cam-cylinder Q,
the lever R is swung to one or the other side, thereby shifting the fork U' against

page_text: с
the wheel W, or U" against W", the engagement between the respective fork
and the wheel against which it bears being obtained by springs Vivi, which also
serve to obtain a sudden change of the forks, when the reversal throws them into
gear with the opposite wheel. According to the engagement of the forks U¹ Un
with either the wheel W or W, the direction of motion of shaft. c will be the
same or contrary to that of shaft b, and as simultaneously with the reversal of
motion, the commutation of the current to be measured is operated, as before
described, the recording train will count the deviations caused by the current in
continuous motion, that is, in the same direction. The undue deviations of the two
clock-works, caused by the deficient regulation of the clock-works, still are eliminated
as described with reference to Figure 1.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is :-
1. In apparatus for recording electric currents by registering the deviations of
clock-works or wheel-trains, a device for preventing false records caused by the
undue deviations in the normal speed of the clocks or wheel-trains, said device
consisting of a commutator, which, in determined intervals, changes the direction
of the current in one half of the measuring system, in combination with a
mechanical reversing mechanism, which, simultaneously with the commutation,
reverses the direction of motion of the recording gear, substantially as and for the
purpose set forth.
2. In apparatus for recording electric currents by registering the deviations of
clock-works or wheel-trains, a device for preventing false records caused by the
undue deviations in the normal speed of the clock-works or wheel-trains, said
device consisting of a commutator, which, in determined intervals, changes the
direction of the current in one half of the measuring system, in combination with a
mechanical reversing mechanism, constructed substantially as described with
reference to Figure 1.
3. In apparatus for recording electric currents by registering the deviations of
clock-works or wheel-trains, a device for preventing false records caused by the
undue deviations in the normal speed of the clock-works or wheel-trains, said
device consisting of a commutator, which, in determined intervals, changes the
direction of the current in one half of the measuring system, in combination with a
mechanical reversing mechanism, constructed substantially as described with
reference to Figure 5.
4. In apparatus for recording electric currents by registering the deviations of
clock-works or wheel-trains, a device for preventing false records caused by the
undue deviations in the normal speed of the clock-works or wheel-trains, said
device consisting of a commutator, which, in determined intervals, changes the
direction of the current in one half of the measuring system, in combination with a
mechanical reversing mechanism, constructed substantially as described with
reference to Figures 6 and 7.
5. In apparatus for recording electric currents by registering the deviations of
clock-works or wheel-trains, à device for preventing false records caused by the
undue deviations in the normal speed of the clock-works or wheel-trains, said
device consisting of a commutator, which, in determined intervals, changes the
direction of the current in one half of the measuring system, in combination with a
mechanical reversing mechanism, constructed substantially as described with
reference to Figures 8 and 9.
Dated this 30th day of August 1894.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.