Improvements in or relating to Electricity Meters.
Year: 1899

page_text: Date of Application, 9th Dec., 1899-Accepted, 4th Aug., 1900
Improvements in or relating to Electricity Meters.
A communication from FELIPE SALDAÑA, Electrical Engineer, of 34bis, Rue la
Tour d'Auvergne, Paris, in the Republic of France.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of London,
Chartered Patent Agent, 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 electricity meters as used at present, suffer, as is well-known, from several
drawbacks:
-
The sparks which are produced in the collector rapidly damage this part,
owing to which the apparatus suffers, and its maintenance becomes expensive.
The movable device is very heavy, which results in a loss of sensitiveness as
well as in a rapid wearing away of the pivotting parts.
The constancy of the apparatus continually changes to a considerable extent.
The principal causes of these variations are as follows:-
:-
1. The sparks, the damage and consequent failure or partial failure of the
collector.
2. The changes in the magnetic power of the permanent magnets, whenever
they are employed in the electro motor or in the brake.
3. The modifications in the passage resistances owing to the state of the
pivotting parts, and especially to the damage and changes of the contact surfaces
of the collector and of the brushes, or of any other device used for commutating
of interrupting the current. This inconvenience is of great importance, espe-
cially when the motor- the brake are of little power, or when there is no
braka at all.
4. The different degree of pressure of the brushes on the collector due:-
Either to changes in the flexibility of the brushes without any apparent cause,
or to their displacement, for the purpose of cleaning the collector, in which
case it is absolutely impossible that the brushes could exercise their original
degree of pressure.
This invention has for its object to avoid or overcome all these drawbacks by
providing an' apparatus of substantial construction and easily produced, at a
low price, the object being an electricity meter consisting of an electro motor
having an, oscillatory movement and of a brake.
'
In order to render the following description clear reference will be made, to
the accompanying drawing; which by way of example, represents a convenient
form of apparatus according to this invention.
Figures 1 and 3 are schematic views in elevation and plan respectively,
separated by the line I-II, of an electro motor with oscillatory movement and
of the brake: Figure 3 representing clearly a plan view of the interrupter of
the motor.
Figure 2 is a horizontal section of the brake on the line III-IV of Figure 1.
In the accompanying drawings like letters indicate like parts.

page_text: The apparatus is composed of the following principal parts.
1 is a fixed coil of an electro magnet with two windings of fine wire.
2 is the core of the electro magnet of coil 1 solidly connected with the shaft
of the apparatus.
3 and 3 are masses eccentrically placed or formed on the core 2 and arranged
in the same direction and in the same plane.
4 and 4 are coils of stout wire through which the whole of the current passes
for the purpose of measuring.
5 and 6 are insulated fixed contacts.
7 is a brush or rubber pivotted at 8 and oscillating between the two contacts 5
and 6.
1
9 is the armature of the electro magnet 11, of the coils 10, actuated by the
said electro magnet and by the motor, said armature being mounted on a pivot a
in suitable bearings.
10 and 11 show the coils and electro magnets which serve to actuate the
brush 7, to compensate the passive resistance and to neutralize the effects of
the variations in the value of the passive resistances.
12 is a solid rod eccentrically connected with the shaft of the apparatus,
which actuates the armature by means of a fork 13.
14 is a rod fixed to the brush 7 serving to communicate to the brush 7, by
means of a fork 15, an oscillatory movement.
16 and 17 are stops which limit (in either direction) the oscillation of the
armature 9.
18 is the shaft of the apparatus.
19 is the casing of the brake.
20 is the brake disc or plate, and
21 is a partition of the brake.
A
In order to facilitate the understanding of the connections the upper part
of the apparatus (Figure 1) is represented in plan view in Figure 3, because
these parts are not seen in the figure representing the whole apparatus.
counting device or register, ratchet wheel and pawl are employed as in an
ordinary meter, but are not represented in the drawings, with a view to render
the latter clearer.
The double windings of the coil have been adopted in order to avoid self-
induction, which would invariably be produced when commutating the current
if there were only a single winding.
It is well-known that in a coil with double-windings, .c. where two vires
are arranged side by side, the currents flowing in opposite directions, that when
the current is broken in one of the two windings, such breaking of the current
will not produce self-induction.
This result is utilised on the one hand to prevent the sparks of the outer
current, and, on the other hand, for the purpose of changing, the polarity of
the core 2.
For this purpose the entering end of one of the two wires forming the
windings of the coil, communicates with the exit end of the other wire as well
as with one of the two principal conductors. The two other ends of the windings
communicate with the contacts 5 and 6, respectively. These contacts com-
municate with the other principal conductor by means of the brush 7.
When the said brush happens to be at the same time in touch with the two
contacts, the current flows through the two windings in opposite directions, owing
to which no magnetic effect is produced in the core 2; when the brush 7 is in
touch with only one of the contacts the core becomes magnetic and of a polarity
opposite to that which would be produced if the brush were to touch the other
contact. In other words the oscillatory movement of the brush produces a
corresponding change in the polarity of the core.
The eccentric polar mass 3 is subjected to the action of the stout wire coils,
through which the current to be measured passes, and the winding of which

page_text: is such that one of them produces an attraction, and the other a repulsion of the
said mass. When the current flows through one of the windings of the coil 1,
the mass 3 tends to turn to the opposite side, the alternate contact of the brush 7
with the contacts 5 and 6 will therefore produce an oscillatory movement of the
core 2, and consequently in the shaft of the apparatus.
The armature 9 pivots about its centre under the action of the electro magnet 11,
and is attracted by the pole of the electro magnet which is nearer to it. When
the two ends of the armature are at equal distances from the poles, i.e. at the
neutral point, the action is reduced to zero. The brush 7 is actuated by the.
armature 9 by means of the rod 14 fixed to the brush, and the fork 15 solidly
united with the armature.
There are two periods in the working of the armature 9, in each direction.
In the first, it is actuated by the motor from the beginning of its course to the
moment where it is moved beyond the neutral point by the fork 13, which is
solidly united with it, and the rod 12, eccentrically connected with the shaft
of the apparatus. In the second, the armature is operated by the electro magnet
from the moment it passes the neutral point up to the time it arrives at the end
of its course.
The distance between the arms of the fork 13 is wider than the diameter of
the rod 12, to enable the armature to carry out the second part of its course
in each direction independently of the motor.
The space between the arms of the fork 15 is also greater than the diameter of
the rod of the brush, so that during the first part of its course, the armature
is independent of the brush, while the latter should not be displaced more than
is necessary.
In the second part of its course the armature actuates the registering and inter-
rupting or commutating device. The necessary force for involving the armature
in the movement of the motor is due to the proximity of the electro magnet of
the interrupter to the eccentric polar mass 31. This effect may be modified by
changing the distance of the electro magnet from the core 2, by giving to it
a position more or less favourable relatively to the eccentric mass, by the addition
of magnetic masses eccentrically or concentrically arranged below the cross part
connecting the straight cores of the electro-magnets by the prolongation of the
cores, by the increase or decrease of the mass of the cross part and by the total
suppression of the latter.
The resistance which the armature offers in the first part of its course to being
actuated by the motor, may be well and easily balanced by the above means,
compensating at the same time the passive resistance arising from the friction
6f the pivotting parts of the shaft of the apparatus, and independently of the
measuring couple.
It is useless to arrange the apparatus in such a manner that the resistance of
the armature in the first part of its movement, and the couple which balances
this resistance, should have the same respective value in every position of the
armature. From this difference it results that the equilibrium between the com-
pensating couple and the action of the electro magnet on the armature takes place
in a position contained between the maximum and the minimum of the resistance
offered by the armature. This affords a means of entirely compensating the
passive resistances without the apparatus being idle.
It is possible to modify at will by different means the change of relation which
exists, according to the position between the couple of the equilibrium and the
action of the electro magnet on the armature.
A spiral spring around the shaft, one end of which is fixed, while the other
is united with the shaft offers a means for producing the relative changes men-
tioned above.
The electro magnet of the interrupter may be replaced by two solenoids, or by
a permanent magnet. The variations in magnetic force in the latter.do not change

page_text: the relation which exists between the couple of the equilibrium and the action
of the magnet on the armature.
If the couple of the equilibrium and of the compensation of resistance were
obtained by other means than those of the electro magnet, the electro magnet
would have to follow the same modifications as regards value as those of the
compensation means. If the electro magnet is substituted by a permanent magnet,
the latter not being able to follow the changes of compensation, the constant of
the apparatus would be interfered with by the variations in voltage and by the
change of the magnet.
As will be seen from the preceding description the passive resistances are
entirely compensated, and the change in the value of the resistances of the inter-
rupting and registering devices produce no effect whatever as rgards the exactness
of the apparatus, since they are altogether independent of the measuring device.
Even a small current passing through the coils of the thick wires will be suffi-
cient to disturb the equilibrium of the system, and the shaft of the apparatus
will turn in one or in the other direction according to the contact which happens
to be in contact with the brush. In this movement the shaft will involve the
armature until the latter passes the neutral point, at which moment it is rapidly
attracted by the other part of the electro magnet which is then nearer to it.
In the second part of the movement of the armature, the brush changes con-
tact, and the motor will proceed in the opposite direction and so on.
It is clear that the derivation coils may be placed in the same circuit or in
independent circuits, with or without additional resistances.
If the iron of the core is laminated the apparatus may serve for alternating
currents. When the iron is magnetised to saturation the apparatus measures
intensity only.
When the iron is sufficiently removed, within the limits of variation of voltage,
from the point of magnetic saturation, the apparatus will measure energy. The
inconveniences connected with the employment of iron in the core 2 effect the
variations of voltage alone, which are, or should be very small, these incon-
veniences therefore may be considered as negligible quantities.
The arrangement of a movable core is advantageous from the point of view of
simplicity of construction and of the action of the motor.
It is possible to replace it by a galvanometric bobbin, without iron core, or by
a system consisting of one or more coils, and in this case it will be possible to
employ with great advantage a combined electro-magnet with double application,
as described above.
The parts of the apparatus may be modified in a variety of ways without how-
ever changing the principle of the invention.
The eccentric prolongations may have different forms and may also be placed
in different planes.
It is possible to do without one of the polar eccentric masses, and to subject
the other to the double action of the stout wire coil and to that of the electro
magnet of the interrupter.
The armature may be polarised or may be replaced by a magnetic mass placed
between the poles of the electro magnet and fixed to a lever arm.
The forks and the rods of the motor and of the brush may be replaced by any
other suitable mechanical device, inasmuch as the invention is not based on
details of construction.
In the case of distribution by three conductors the stout wire coils may be of
double winding, or a system of stout wire coils in combination with an eccentric
polarising mass 31 may be added. In the case of distribution by means of 5 con-
ductors, the two eccentric masses are utilised and a double system of stout wire coils
with double winding is provided.
In order to be able to change the constant when the tariff is changed, there is
provided in the stout wire coils a shunt of corresponding value, suitably con-
nected to the armature of an electro magnet or of a solenoid actuated by the

page_text: central stations or in the house of the customers by means of an automatic switch
in such a manner that the operation of the shunt gives the reduced tariff.
It is also possible to use, by way of variation, with satisfactory results, the
system of the coil 1 and the electro magnet serving to actuate at the same time
the interrupter or the commutator and to compensate the passive resistances, in an
arrangement in which the armature of the electro magnet of the interrupter would
be independent of the motor.
The interrupter, in this arrangement, consists of an electro magnet, or of a
permanent magnet, and an armature polarised by means of a coil with double
windings of fine wire similar to the coil actuating the core 2. A brush is fixed
to the armature which is in the same relation with the contact and the actuating
coil of the core, under the same conditions as those of Figure 1.
The current flows through the two conductors of the polarised coil, and at
the end of the course of the motor, in each direction, a small rod or pin solidly
connected with the shaft of the apparatus, separates, from a fixed contact, in
communication with one of the principal conductors, a plate, preferably of silver,
acting as a spring in communication with one of the conductors of the polarised
coil. At this moment the current is broken in this conductor, the brush changes
contact and the motor turns in the opposite direction, while at the same time,
the silver plate returns to the fixed contact.
At the end of its course the motor separates from the fixed contact, under the
same conditions, another silver plate which communicates with the other con-
ductor of the polarised coil. The other conductor is then cut out of the circuit
and the brush returns to the other contact from which it had moved and so on.
In order to avoid the drawbacks of the present brake systems a new description
of brake is employed, based on the compression and rarification of air in a space
more or less completely closed.
The brake consists of a plate of metal or of other suitable material mounted
by one of its sides on the shaft of the apparatus, and so arranged as to be
movable radially within a cylindrical chamber provided with a radial partition,
The dimensions of the cylindrical space should be sufficiently large so as not to
interfere with the oscillatory movement of the plate, whilst keeping at the same
time, however, the free space sufficiently small for the purpose of producing within
the cylindrical chamber a compression of the air corresponding to the direction
of rotation, and a rarification of the air in the other direction.
Figure 2 represents a horizontal section of the brake which is also shown in
the figure representing the whole of the apparatus. In this figure:-
19 is the cylindrical space or brake box;
18 is the shaft of the brake and of the whole system;
20 is the radial plate; and
21 is the radially arranged partition.
-
This space or chamber instead of being supplied with only one plate and one
partition may be supplied with two or more of both. Further only one half or
any other portion of the cylindrical capacity may be employed. The reduction
of the free space between the plate and the casing tends to retard the movement of
the apparatus;
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondent and in what
manner the same is to be performed I declare that what I claim is:-
1. An electricity meter characterised by the combination of an electro motor
with a brake substantially as described or illustrated in the accompanying
drawing.
2. In an electricity meter, an oscillatory electro motor, comprising an electro
magnet composed of a movable core of iron or other suitable magnetic metal or
magnetic alloy, solidly connected with the shaft, having one or more polar masses
of suitable form eccentrically arranged therein, preferably in the same plane and

page_text: in the same direction, the core being adapted to be energised by a fixed derivation
coil of fine wire wound in the ordinary manner or having two windings side by
side so connected with each other that when the conductors are traversed at the
same time by a current, the action of one neutralises that of the other, these
conditions of interrupting the current effecting the double object of preventing
self-induction and of changing the polarity of the core, by producing, when the
current is broken, in only one of them, a magnetising influence opposite to that
which would be produced by breaking the current in the other, substantially as
described.
3. In an electricity meter an oscillatory electro motor comprising an interrupter
or commutator actuated by the armature and an electro magnet energised in
derivation, the armature being arranged to oscillate when attracted by one pole
in one direction, and by the other in the opposite direction, this armature passing
through two different phases in its movement and in each direction, the armature
being subject first to the double action of the electro magnet and the motor, the
latter by suitable mechanical means separating it from the pole at the
moment when it passes the neutral point from which moment it passes
through the second phase of its course and is then attracted to the end
of its course by the other pole of the electro magnet, without being acted upon
by the motor; the armature actuating, in this movement, the interrupter and the
registering device, the core of the electro magnet being preferably non-saturated,
so that there may be always the same relation between the action of the electro
magnet on the armature and the couple which balances this action, substantially
as described.
4. In an electricity meter, an oscillatory electro motor comprising an inter-
rupter or commutator with one or two electro magnets (or solenoids or a permanent
magnet) so arranged that it produces owing to its position and its proximity to the
movable measuring device, a couple sufficing to balance the resistance which
the armature offers to being actuated by the motor during the first part of its
course and in both directions, and compensate the passive resistances; the value
of the couple being capable of modification by the more or less favourable con-
ditions depending on the measuring devices, substantially as described.
5. In an electricity meter, an oscillatory electro motor comprising an inter-
rupter or commutator in which the brush or movable contact is connected with
a polarised armature of an electro magnet, or solenoid or permanent magnet, the
polarisation being obtained by means of a coil, the two windings being traversed
by a current flowing in opposite directions, the motor breaking the current of
each winding at the end of its course in either direction, separating, in doing
so from two fixed insulated contacts, two insulated plates, acting as springs (one
plate for each direction or motion) and corresponding to two conductors of the
polarisation coil, the two fixed contacts, or a contact common to two flexible con-
tacts, communicating directly or indirectly with one of the principal conductors,
the other principal conductor communicating, directly or indirectly with the
point of connection of the wire which forms one of the two conductors of the
polarisation coil and of the exit end of the wire forming the other conductor,
substantially as described.
6. In an electricity meter an oscillatory motor, comprising an electro magnet,
solenoid or permanent magnet serving to actuate directly or indirectly the brush
of an interrupter, said electro-magnet being arranged sufficiently near the movable
part as to exercise on the latter an effect which is added to the effect of the
stout wire coil and serves to compensate the electrical passive resistances of the
apparatus, substantially as described.
7. In an electricity meter a brake consisting of one or more radial plates of
metal or other suitable material, mounted on the shaft of the apparatus in such
a manner as to be able to rotate in a cylindrical chamber provided with one or
more radial partitions, the plate fitting the chamber sufficiently closely so that
whilst it is not impeded in its oscillatory movements, at the same time, the free

page_text: space is sufficiently small to produce in the cylindrical chamber a compression
before the plate in its rotary movement and a rarification of air behind it sub-
stantially as described.
4
י
Demo 1800
BOULT, WADE & KILBURN,
Agents for the Applicant.