Improvements in Electric Meters.
Year: 1891

page_text: Date of Application. 2nd Mar., 1991-Accepted, 11th Apr., 1891
COMPLETE SPECIFICATION.
Improvements in Electric Meters.
I, MAURICE KOECHLIN, of Vevey, Switzerland, 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 a construction of electric meters which is based on the
principle of the Wheatstone bridge.
Referring to the diagram shewn at Fig. 1 of the accompanying drawings, L is
the lamp circuit, S S two solenoids forming resistances, R a fixed rheostat absorbing
in the lamp circuit less than volt; a variable rheostat, G G two solenoids
forming the galvanometric branch.
If the relation of the resistances is such that-
L
=
R
no current will circulate
7"
in G G but if the relation is modified by the variation of the resistance of the lamps
in I, a current will circulate through G in one direction or the other, according as
the resistance L is increased or diminished.
This
E
TS
In my electric meter which is shewn in vertical section and sectional plan at
Figs. 2 and 3 the solenoids S S excite a soft iron core N in the field of which two
solenoids G G are movable. It results from this, that if the equilibrium of the
bridge is broken, the solenoids G G are repelled or attracted, and by their move-
ment displace the rheostat to such extent that the equilibrium is again established.
At the same time that this movement occurs, a roller g movable on a circular
table P turning under the action of a clock-work, is moved correspondingly to a
new position. The table P is turned by the wheel W. The roller g is mounted to
slide along an arbor a, to which it imparts rotation by a feather and groove.
arbor a drives the wheels of the counter or totalizer. Binding posts 1 and 2
(Figs. 1 and 3) comununicate with the lamp circuit L, whilst the binding posts 4
and 5 (Fig. 3) are in communication with the source of electricity. The binding
posts 5 and
are electrically connected in any manner. The rheostat R is formed
of a ribbon of German silver connected between the binding posts 1 and 4.
The variable rheostat r is arranged in such manner that for equal mechanical
displacements it gives equal variations of resistance. To this end (Figs. 4 and 5)
this rheostat is formed of three discs of vulcanized fibre; the middle disc which is
of a smaller diameter than the others, is formed with regular teeth, and also with a
circular series of holes. Between the teeth and through the holes is placed a helical
coil of iron wire c of which one extremity is insulated whilst the other is in com-
munication with the metallic pulley ml. The two outer discs are connected by a
sheet iron ribbon B. A drop of mercury m is imprisoned in the remaining space.
It is obvious that on the rotation of the discs, the drop of mercury will remain always
at the lowest point and varies the interposed resistance, that is to say, the length of
the iron wire cover which the current passes in flowing between the pulley m and
the iron ribbon B. The rotation of the discs is effected by means of cords, ¹, ¹,
and of pulleys driven by the solenoids G G. These same cords also move the
roller g.
C
The endless cords 221 are simply stretched over the pulleys z" of the arbor t and
are connected to the roller which they consequently cause to travel with them,
while the cord z which is of silver, is connected to the army of the support of one
of the solenoids G. This cord z passing over guide pullies and the metal
pulley m¹ establishes an electrical communication between the solenoids G and the
iron wire c of the variable rheostat, and in passing over pulley of arbor ɩ, its
motion is imparted by the latter to the roller 9.

page_text: The movements of the roller are consequently proportional to those of the
rheostat r, and hence inversely proportional to the resistances of the lamps L. As
the roller travels farther from or nearer to the centre of the table, its speed of
rotation increases or decreases in the same ratio. In order to avoid placing the
roller at the centre of the table when the consumption falls to zero, which
would prevent mounting the table between pivots and would also wear facets on the
roller, it is given a differential movement in the manner represented in the vertical
section at Fig. 6. This differential movement is imparted by a planet gear so
arranged that the movements of the totalizer shall be equalto the difference between
the speed of the roller and that of the table. In this manner, when the roller is at
a distance from the centre equal to its own radius, the totalizer rests motionless
while the roller still turns on itself. The small wheel d which turns with the
intermediate wheel drives the wheels of the totalizer, the wheel turns with the
table, and the wheels and n turn with the roller but in the contrary direction.
In order to obtain the rotation of the wheels and n in the contrary direction to
that of the roller g; a bevil wheel is fixed on the arbor a and this wheel transmits
its motion to the wheel & by means of the bevel pinion whose axis is carried by
the arm a which supports the arbor a.
A clock dial is provided to give assurance to the correct running of the clock-
work, and in case of its derangement to afford means for correcting the reading of
the totalizer.
In order to complete the description of my meter, I have yet to indicate how the
electric connections are established between the several elements of my meter in
order that these connections may realise the results of the Wheatstone bridge
represented diagrammatically in Fig. 1.
These connections are made as follows:-(see Fig. 3).
The binding post 1 is connected to the lamp circuit L, as also to the rheostat R,
and leads the current by means of a flexible conductor to the two coils G G
connected in series, and the current passes out from the second of these coils by the
frame of the latter and through an army projecting from this frame and provided
with a groove in which is fixed the end of the cord z which consists of a silver wire.
By this cord, which passes over the conducting pulley me of the variable rheostat r,
the current is led on the one hand into the wire c of this rheostat and passes by the
drop of mercury m, the metal ribbon B, a metallic band. B' (Fig. 5), a conducting
ring B and a brush B (Fig. 3), into the conductor v connected to the binding
post 4, and on the other hand from m' and into the axis t carrying the pulleys,
and passes by the supports of this axis and the conductors uu into the fixed
solenoids S S connected in parallel, through the wires u u' to the binding post 2.
The contact of the silver wire with the pulley, m¹ of the variable rheostat-con-
stitutes consequently the point of bifurcation 3 of the diagram represented in Fig. 1.
As seen in Fig. 3, the sliding movement of the roller on the arbor a during the
displacement of the coils G G is imparted by the travel of the endless cords ==
driven by the pulleys fixed on the axis t whenever this axis is turned under
the influence of the movements of the cord z.
2
The arbor a which carries the roller g is carried by a support a' pivotted at
(Fig. 2) to the frame of the meter, and provided with an arm carrying a counter-
weight e in such manner that by the adjustment of this counterweight the pressure
exerted by the roller g against the table P may be regulated at will.
Figs. 7 and 8 shew an elevation and plan of another arrangement for the trans-
mission of the motion to the counter.
In this arrangement two rollers g g are arranged diametrically opposite each other
on the plate P, which receive a regular motion from a clockwork. These rollers y g
bearing on the plate P; are consequently made to rotate in contrary directions, and
they are kept at a constant distance from each other by their collars and the
cords. Each roller g can slide on an arbor a and, when variations in the
consumption of electrical energy occur they are simultaneously displaced by the
cords so as always to remain the same distance apart.

page_text: In this arrangement it is the difference between, the speeds of the two rollers:gg
which is transmitted by means of a differential motion to the mechanism. of the
counter. For this purpose the arbors a a: carrying. the rollers gg carry spur
wheels gearing with spur wheels u" " formed in one with the bevil wheels h³ n¹
which transmit to the counter by an intermediate wheel the difference of the two
speeds, in a manner similar to the preceding arrangement. By this arrangement
the wearing of facets on the rollers will also be avoided, as when these are placed
at equal distances from the centre of the plate they turn without imparting any
motion to the counter.
It is evident that this arrangement will give differential speeds twice as great as
those with a single roller, but on the other hand it requires double the expenditure
of energy to make two rollers slide on the plate instead of only one. The entire
system of the bridge picce a" of the arbors a, the rollers g g and their wheels is
guided in the vertical direction by a collar c¹¹, so that its weight is transferred by
the rollers to the revolving plate P.
If the weight should be too great, it might be partly balanced by helical springs
from which the system would be suspended, and the tension of which might be
regulated in any suitable manner.
It will be understood that this resistance-integrating apparatus may be used in
series installations as well as in those in parallel.
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. An electric meter, consisting of a fixed rheostat, a variable rheostat, two fixed
solenoids, and two moveable solenoids situated in the field of a soft iron core excited
by the fixed solenoids, the said fixed and moveable solenoids and the said rheostats
being combined with each other and with a distributing circuit and a source of
electrical energy in such manner as to form an automatic Wheatstone's bridge, such
that when the equilibrium of the bridge is broken, in consequence of the increase or
decrease in the consumption of electrical energy, the fixed solenoids will exert upon
the moveable solenoids attractive or repulsive forces which effect the simultaneous
displacement of the variable rheostat until the equilibrium is again established, and
of a revolving roller sliding on an arbor connected to a registering mechanism, such
roller being made to bear upon and be rotated by a revolving table or disc over
which its arbor is radially placed so that the number of revolutions of the roller and
its arbor and consequently of the counter in a given time will be proportional to
the quantity of electrical energy consumed, substantially as described.
2. In an electric meter, a variable rheostat formed of three discs of vulcanized
fibre of which the middle one is of a less diameter than the two outer ones and
carries at its periphery a helically wound iron wire, while the other two discs are
connected by a sheet iron band leaving an annular space between it and the middle
disc, in which is contained a globule of mercury which constitutes a moveable
electric contact between the iron wire coil and the iron band, substantially as
described.
3. In an electric meter the combination of a revolving table or disc actuated by
clockwork mechanism, a moveable roller resting ou the said disc capable of sliding
upon a radially placed arbor, and a differential inechanism interposed between the
said disc and arbor and the registering mechanism and so arranged as to transmit
to the later a motion equal to the difference between the motion of the disc and
that of the roller, substantially as and for the purpose herein described with
reference to Figs. 2 and 6 of the accompanying drawings.
4. In relectric meter, the combination of a table or disc rotated by clockwork,
two rollers sliding on two diametrically opposite arbors and rotated by the said
disc, a variable rheostat which effects the displacement of the said rollers upon their
arbors on the occurrence of variations in the consumption of electrical energy,
and a

page_text: differential mechanism whereby the difference between the speeds of rotation of the
two arbors is transmitted to the registering mechanism, substantially as described
with reference to Figs. 7 and 8 of the drawings.
ABEL & IMRAY,
Agents for the Applicant.