Improvements in and relating to Apparatus for Measuring Electric Currents.
Year: 1889

page_text: Date of Application, 12th Feb., 1889-Accepted, 20th July, 1889
[Commumicated from abroad by HENRY HENDERSON CUTLER, OI Newton,
Massachusetts, United States of America.]
Improvements in and relating to Apparatus for Measuring
Electric Currents.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, 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 relating to an electric meter is embodied in an apparatus comprising
a device for indicating the quantity of current flowing through a conductor at any
given time and also for measuring the total product of the quantity of current flowing
into the time during which such current continues to flow in any desired interval of
time.
The device employed for indicating the quantity of current consists essentially of
two wires substantially similar to one another in diameter, length and material, and
subjected to equal tension in the direction of their length, one of which wires is
traversed by the current to be measured and is thus heated and is caused to expand by
the current flowing through it, the amount of said expansion varying with the amount
of the current.
The said wires are connected with a pivoted yoke or lever provided with a pointer,
which yoke is caused to rock on its pivot and produce a movement of the pointer
as the length of one wire relative to the other changes.
The pivot of the yoke is acted upon by a spring or equivalent that produces
tension upon the wires so that any expansion or contraction that is shared equally
by both wires simply causes a bodily movement of the yoke without rocking on its
pivot or producing angular movement of the pointer which thus responds to only tho
difference in expansion produced by the current flowing through one wire.
The pointer will thus assume different angular positions for different quantities of
current flowing through the wire, and when used for example with a system of electric
lamps supplied by the current passing through the meter from a main circuit capable
of supplying a large number of lamps, the said pointer will assume different positions
for each different number of lamps that may be in operation in the supplied
circuit.
In order to indicate the product of the quantity of current into the time during
which the current is used, or in other words to measure the ampere-hours of current
used in a given period of time, the said pointer cooperates with a time motor or clock
and with an indicating train of wheel work so arranged that the number of move-
ments of the indicating train during a given period of time, depends on the position
of the pointer and is proportional to the current at that time indicated by the
pointer.
Assuming for example that the part of the clock motor that causes the indicating
train to be moved rotates once in six minutes, it will, if one lamp be lighted and a
corresponding current be flowing,.produce one movement of the indicating train of
wheel work at each six minutes.
If two lamps be lighted it will produce two movements in each six minutes and
so on, so that the said indicating train will at the end of any given period show the
total product of the number of lamps that have been operating into the time that.
they have operated.
The clock movement is shewn as actuated by the current and arranged to run only
while the current is flowing, means being provided for automatically starting the

page_text: clock when the pointer moves to indicate the smallest amount of current that is used,
and to stop the clock when the current wholly ceases in the supplied circuit.
In meters such as just described that depend for their operation upon the heating
action of the current on a conductor, the range of efficient operation of the meter is
limited as a conductor that is capable of responding to small currents would be over-
heated and possibly destroyed by very much larger currents and this invention
includes other appliances by which the meter is made capable of indicating with
sufficient accuracy for a very large current said appliances being applicable to meters
having sensitive and indicating devices of other kinds than previously referred to as
this part of the invention relates especially to the combination of the meter proper
with the circuits from which the current is supplied and in which it is used, and with
devices for changing and controlling the relation of the meter proper to the said
circuits.
When the capacity of the meter must be increased it has two or more sensitive
portions placed in series in the circuit the current supplied to which is to be measured;
one of said sensitive devices being proportioned to respond to comparatively small
changes in the current and the next in the series being capable of carrying a larger
current without injury than the first, and cooperating with a switch or circuit changer
which when the meter is acted upon by greater current than that which can be
safely carried by the first device closes a short circuit around the first device which
is thus relieved from carrying the larger currents while its resistance is removed from
the circuit.
The capacity of the meter might be further increased by providing a third
sensitive device standing in the same relation to the second that the second does to
the first but for most purposes it is preferable to adopt the following plan, which is
applicable to various kinds of meter having a limited capacity of range of currents
with which they operate efficiently.
In such plan the entire set of lamps or translating devices the operation of which
is to be measured are divided into a number of separate sets, each of a number
within the capacity of the meter, each of which sets is supplied by a separate branch
from the main leads or supplying conductors and the clock or time mechanism of the
meter is made to operate circuit changing devices by which the sensitive part of the
meter is introduced into these circuits successively.
The invention also consists in appliances by which an electric meter may be made
to indicate for machines or instruments of any kind, the aggregate of the product of
the number of machines or instruments operating into the time of operation of said
devices, during a given period of time and the apparatus herein shown for the purpose
of illustrating this part of the invention is arranged to indicate the number of lamp
hours that the lamps of a given set of are lamps have been used, although the
apparatus is equally capable of indicating the product of time of operation into the
number of instruments operated, for any given set of instruments or inachines, as the
operation of the meter depends upon the movement of a switch or other device by
which the lamp, machine or instrument, the time of operation of which is to be
measured, is thrown into and out of operation.; and not directly upon the condition of
the current that operates the translating device itself provided the instrument is an
electric translating device.
In order to accomplish this result in accordance with this invention an auxiliary
circuit is employed containing or cooperating with an electric meter and a number of
electric switches or equivalent devices, each mechanically connected or otherwise
dependent for their condition upon the operation of the starting and stopping device
by which the apparatus the time of operation of which is to be measured, is controlled
and each when operated making a change in the current passing through the
meter.
Figure 1 is a front elevation of an electric meter embodying this invention.
Figure 2 a side elevation of the time motor or clock with one of the frame plates
removed to show the working parts.
:)

page_text: Figure 3 a detail of the counting or indicating part.
Figure 4a diagram representing the circuit connections for the clock and
meter.
Figure 5 is a diagram representing a portion of the sensitive and counting parts of
the meter and circuits and switches co-operating therewith, when larger currents than
can be measured by a single sensitive device are used.
Figure 6 a side elevation of a portion of the clock as modified for a meter of
increased capacity.
Figure 7 a side elevation of the shafts of said clock by which the counting and
circuit changing devices are actuated, and a portion of the devices operated by said
shafts.
Figure 8 a side elevation of one of the circuit chambers by which the sensitive part
of the meter is introduced into different circuits successively.
Figure 9 a detail of the clock mechanism.
Figure 10 a detail showing the switch for short circuiting the more delicate
sensitive device of the meter.
Figure 11 a diagram showing the application of a meter for measuring the time of
operation of are lamps or translating devices of the kind that are used in series in a
circuit, and
Figure 12 a diagram showing the application of the meter for measuring the time
of operation of instruments or machines not necessarily operated by an electric
current.
The part of the meter directly affected by the current is composed of a wire a,
which with a similar wire a¹ is fastened at one end as shown at a³, as to the rigid
frame work A of the instrument, both said wires being stretched from said points of
attachment to a yoke or lever b, with which each is connected by a stirrup or similar
device a, a, the said yoke or lever b, being itself pivoted upon a stirrup 6 acted upon
by a tension device shown as a spring e which tends to stretch both wires a, a¹ and
subject them to equal tension.
The wires a, a are completely insulated from one another and are preferably
composed of German silver as that is sensitive to the action of an electric current
passing through it, and as the wires are of substantially the same size, length, and
material, and subjected to the same external conditions it is obvious that any expan-
sion or contraction shared in by both wires equally will, simply produce a bodily
movement of the lever b without turning it on its fulcrum, such expansion and
contraction being accommodated by the yielding of the tension device o.
Consequently changes in temperature due to external influences will produce no
rocking movement of the lever b.
Any expansion or contraction, on the other hand, of one of the wires that is not
shared in by the other wire will cause a rocking movement of the lever b, which is
provided with a long pointer d, that has the same angular movement as the lever b, so
that its extremity indicates a relative change in the lengths of the wires a, a¹ but on a
much larger scale, the indication being multiplied in the proportion of the length of
the pointer d, to the distance between the points of attachment of the wires a, a¹
with the lever b.
The wire a is interposed in circuit (see Figure 4) between the main or supplying
conductors 2, 3 and the translating devices to which the current is supplied from
said main conductors, and is consequently traversed by all the current consumed by
the translating devices; the said wire being heated and expanded by the said current.
in the well known manner and the amount of expansion varying with the quantity
of the current in a ratio that can readily be determined by experiment, it being
sufficient for purposes of comparative measurement that the positions of the pointer
for different known currents be once observed and marked after which the current at
any time flowing will be known by the position of the pointer.
Such a graduated scale for the pointer is represented at being shown as sup-
ported on a swinging frame the purposes of which will be hereinafter explained.

page_text: When as is usually the case a current of substantially constant EM F is employed to
operate a greater or less number of translating devices arranged in multiple are the
pointer d, will move by successive steps as the number of translating devices is varied, and
for convenience in description the instrument is represented for indicating for any
number from one to ten of translating devices such for example, as incandescent lamps.
In order to indicate the total product of the translating devices into their time of
operation the said pointer d is arranged to act as an intermediate device between an
indicating train of wheel work B and a time measuring actuator e for said train in such
manner that the amount of movement of the train B, during any period of movement
of the actuator e, will vary according to the position of the pointer d and consequently
in accordance with the number of translating devices that are in operation during
such period.
A time motor or clock by which the actuator e is propelled will be hereinafter
described, it being sufficient for the understanding of the operation of the indicating
devices next to be described, to know that the said actuator e, which is in the form of
a drum makes complete rotations at definite time intervals as long as any of the
translating devices are in operation and it may or may not also continue to run while
the said translating devices are not in operation.
The said drum e is arranged below the pointer d, so that the end of the latter in its
movement passes from end to end of the said drum which is provided with a number
of projecting blades or wings e¹ of different length as clearly shown in Figure 1 the
said blades all extending from one end of the drum but terminating at different
distances from the other end of the drum one only extending the entire length of the
drum.
The pointer d is made thin and flexible or has its end hinged so that it can be
easily moved some distance in the direction at right angles to the plane in which it is
inoved by the lever b for the purpose of indicating the quantity of current, which
side-wise or lateral movement will not change its angular or current indicating
position.
When no current is flowing and both wires a, a¹ are exposed only to external
conditions the pointer will be in the position shown in Figure 1 and wholly at one
side of the drum e.
When one translating device is thrown into circuit the corresponding movement of
the pointer d will bring it over the adjacent end of the drum e, in position to be
struck by the one plate e, that extends the entire length of the drum so that the end
of said pointer d will be swung aside or moved laterally once at each rotation of
the drum.
If two translating devices are set in operation the pointer will move a step further
along the drum so that the next shorter blade el will also strike it thus producing two
lateral movements at each rotation of the drum, and so on for cach additional
translating device set in operation the pointer will receive an additional lateral move-
ment during each rotation of the drum.
.
The number of movements of the pointer is therefore equal to the sum of the
number of lamps in operation during each rotation of the drum e.
This number of movements is indicated by the train B which may be like the
indicating train of any meter and is operated by the following mechanism best shown
in Figure 8.
The end of the pointer d, rests at one side of the swinging frame f so that each
internal movement of said pointer produced by one of the blades of the drum produces
a corresponding swinging movement of the said frame which extends across the entire
traverse of the pointer so as to be operated by it in whatever position it may be.
The said frame has an arm f¹ provided with a pawl 2 engaging a ratchet on
the first arbor of the train B (see Figure 3) so that it advances the said ratchet one
tooth or step at each swinging movement of the frame corresponding to a lateral
movement of the pointer d, and the total number of these step advances which will be
indicated by the train of wheel work in the usual manner, thus indicates the total

page_text: number of lateral movements of the pointer d which returns to the original position
after each blade passes it and before the next blade engages it.
So far as the operation of the actuating drum e and indicating train B is concerned,
the pointer & might be moved angularly by other means than the wires a, a¹ it being
only necessary that it should be moved to the different annular positions corresponding
to different quantities of current in use.
The clock or time motor by which the drum e is driven is shown in this instance as
actuated by the current and consists essentially of a train of wheel-work g, g',g², g³
the pinion of which is on a shaft having connected with it a rachet as best
shown in Figure 2.
This train of wheel work causes the drum e to be moved much more slowly than
the ratchet which is actuated with a step by step movement by a pawl i carried by a
lever i, pivoted at 2, and connected by a link with the armature of the magnet &
which is of the solenoid type giving a comparatively long movement of its armature
or the core pieces that are drawn into the coils.
In order to regulate the time of the intermittent movements of the armature, so
that the step by step movement of the rachet h, and consequent movement of the
drum e, may be uniform in equal periods of time, the, circuit of the said magnet k, is
controlled by a vibrating governor shown as a balance m, provided with the usual hair
spring ml, and co-operating with an anchor or escapement lever m², which cooperate
with an escape wheel m³, that is loose on the actuated shaft h, of the clock train but is
connected with the said shaft by a spring m', so that each time the ratchet /', is
advanced one step the spring is strained and wound up, tending to cause the escape
wheel to follow in the same direction.
The said escape wheel thus gives the necessary impulse to the pallets of the
lever m², to maintain the vibration of the balance and the said lever m², is provided
with a circuit closer n, controlling the circuit of the magnet k, and causing the
same to be energized and demagnetized at each complete to and fro vibration of
the lever, and to thus advance the ratchet one step at each such vibration and
maintain the force of the spring that acts on the escape wheel substantially uniform
at each vibration.
By this construction it will be seen that the power that drives the train of wheel
work and actuating drum e for the indicating train is derived from the magnet k,
which may have sufficient power to do the work be it more or less, while the
power that drives the regulator or time measuring part m, m2, m³, is derived from the
spring m, and does not vary with the amount of work done by the drum e.
As there is no need of having the clock movement run except while the current is
being used by the translating devices the circuit of said magnet may be controlled by
a circuit closer o, controlled by the pointer d, as shown in Figure 1 being opened
when the said pointer is in the zero position or when no current is flowing, but
being closed by the movement of said pointer which occurs when the minimum of
current is pern:itted to flow through the translating devices.
In order to insure the proper starting and stopping of the balance m, a lever p, is
provided having a slender yielding finger p', which rests against and engages the.
surface of the balance when the magnet k, is demagnetized, the said lever p being
controlled by the lever i, by which the ratchet 1, is actuated.
The said lever p, has a projection p², that resis over the lever i, so that when the
latter is moved by the attraction of the magnet k, the said lever p, is moved and
its finger pl, swings the balance m, so as to start its vibratory movement.
In order to prevent the lever p, from interfering with the balance after it is once
started and while the clock is running continuously a support p³, is provided for
said lever which is retained disengaged from it by the pointer d, when in the zero
position but is permitted to drop beneath the said lever p, when the pointer moves
away from its zero position and the magnet k, receives its first impulse which raises
the lever p, sets the balance in vibration, and applies the power through the
spring m, to maintain the vibration of the balance.
The circuits of the parts thus far described are represented in diagram in Figure +,

page_text: in which 2 and 3 represent the main current supplying mains or leads and 40 and 50
the two members of the supplied circuit between which the translating devices T are
connected in multiple are in the usual manner.
The wire a, of the current indicator is included in circuit between one of the main
leads as 2 and one member of the supplied circuit as 40, so that all the current going
to the supplied circuit passes through it.
-
The magnet, operates in an independent branch between the main leads 2, 3,
being of high resistance so that only a small quantity of current is consumed by it.
One terminal of said magnet is connected as shown at 25 with one of the main
leads as 2 and the other terminal of said magnet is, connected by conductor 26
with a contact piece insulated from the frame work of the clock which is itself
connected by conductor with the other main lead 3.
The spring member n, of the circuit closer that is operated by the time governor
of the clock is in electrical connection with the metallic parts of the clock and thus
through conductor 27 with the main lead 3 and consequently when the said spring n
engages the contact t, in the vibration of the governor, the circuit 25, 26, 27, is closed
through the magnet k, causing the said magnet to be energized so as to actuate the
ratchet, as before stated, and when the spring a, moves away from the contact t,
the circuit is broken and thus permits the magnet to be demagnetized and its armature
retracted so as to be ready for another movement when the circuit is again closed at
the next vibration.
When the clock is stopped upon the arrival of the pointer d, at the zero position the
balance starting lever p, is permitted to fall and engage the balance which comes to
rest with the parts in position to leave the circuit open between n and t as shown in
Figures 2 and 4 and it is necessary to close the circuit by some other means than the
circuit closer n, t, when the clock is again to be started.
This is done by the circuit closer o, which is insulated from the clock frame, but is.
connected by wire 28 to the starting lever p, which is also insulated from the clock
frame but when the clock is stopped makes contact through the surface of the
balance m, with the parts of the clock so that when the circuit closer o, comes into.
contact with the contact t, by the movement of the pointer d from the zero position,
the circuit will be closed through the magnet k, by the conductors 25, 26, t, o, 28, P,
the clock frame, and 27 thus energizing the magnet which gives the first impulse to
the clock, and at the same time lifts the starting lever p, as before stated and permits
it to be held in its raised position by the prop p³, so that the circuit is no longer closed
between the conductors 28, 27, through the starting lever p, and clock frame, and the
magnet, is left wholly under the control of the circuit closers n and t, until the clock
is again stopped by the pointer d, coming to the zero position.
When larger currents are to be used than can be safely passed through the wire a,
if made of sufficiently high resistance to be sensitive to the minimum current used,
the meter may be made and connected in circuit as shown in Figures 5 to 10
inclusive, in which the apparatus is arranged for accounting for any number up to one
hundred lamps.
The lamps or translating devices T operated by the current are then divided into a
number of sets each supplied by branch leads 4, 5; 6, 7; 8,9; 10, 11; the terminals
of which are connected with the main leads as follows:
One terminal of each of said branch circuits namely the terminals 4, 6, 8 and 10
are connected directly with one of the main leads as 3 such connection not being
altered or destroyed during the operation of the apparatus.
The other terminals 5, 7, 9 and 11, are connected directly with circuit changing
switches C which put the said terminals either in connection with a wire 12 connected
directly with the main lead 2, or with a wire 13 connected to the main lead 2 through
the sensitive part of the meter proper.
The said switches, C, are so constructed that they break the connection between the
corresponding branches and the wire 12 when they make the connection with the
wire 13 and the reverse, so that the branches are always maintained, in connection
with the main leads, and the switches C normally maintain the connection with the

page_text: wire 12, and make the connection with the wire 13, and meter periodically, there
being but one of the branches connected through the meter at any one time, and said
branches being connected one after the other with the said meter at definite intervals
of time during the operation of the apparatus.
The sensitive and counting portions of the meter are shown in this instance as of the
same character as already described, but in this instance there are two of the sensitive
devices a, a, that move the corresponding pointers d, and d, over the surface of
drums e, and elo, either one of which pointers is capable of operating the counting
mechanism or indicator B, which thus indicates a number corresponding to the number
of lateral vibrations of which ever one of the pointers d, do, is over the surface of the
corresponding drum and operated by the radial wings or blades thereof.
The wire a is of greater conductivity than the wire a and consequently is less
heated by the passage of the same current, which in one condition of the apparatus
passes through both of said wires, which are connected in series with one another in
the wire 13 that extends from the supplied branches to the main lead 2.
The wire a is of sufficiently high resistance to be sensibly expanded by the heat
produced by the passage of a current sufficient to operate a single lamp; and will
cause the pointer d, to move successive steps along the surface of the drum e as current
is supplied to additional lamps; but owing to the high resistance required to make the
wire sensitive to the current for a single lamp it would be heated to a dangerous
point by the current required for a large number of lamps.
a,
It will, however, operate satisfactorily for a certain limited number of lamps, shown
in this instance as ten, and the wire a¹0, is of such resistance as to be sensibly affected
by the maximum current for which the wire a is intended to operate, so that when a
current sufficient for eleven or more lamps passes through wire 13, the wire a¹0, will,
be sensibly expanded, and will cause the pointer do to move towards and to a position
over the end of the drum elo
The said pointer do operates a switch D, shown as an arm pivoted on a rock
shaft D see Figure 10 and provided with a finger D³, which is caused to enter or
leave a body of mercury contained in a cup D, according as tho said rock shaft is
turned in one or the other direction, and the said rock shaft is provided with an
arm D, that is engaged by a pin or projection at the end of the pointer or by the
pointer itself so that as the said pointer moves towards and from the position slightly
beyond the end of the drum eo, it causes the members D3, D4, of the switch to make
or break a connection between the wires 15, 16, connected with said switch
members.
The weight of the weighted finger D, of the switch arm D, brings the centre of
gravity of said arm above its pivot so that it drops into and reniains in the mercury
cup by the action of gravity as the pointer do, moves away from its extreme or zero
position.
The said wires 15, 16, connected with the switch members D D₁, are also connected :
with wire 13 at each side of the sensitive device a of highest resistance and when said
wires 15, 16, are connected at the switch they constitute a shunt or circuit of low
resistance around the wire a, which then receives an inappreciable amount of current
and moves to the zero point or beyond the position at which it is affected by the
blades of the drum e.
Any current therefore, beyond the maximum current for which the wire a is
intended to indicate will in passing through the wire a¹0, cause a movement of the
pointer do, sufficient to close the switch and cut out the wire a, and also to bring the
said pointer do, into position to be acted upon by its drum e¹ and further additions to ..
the current would cause the pointer do, to move along to different positions on the
drum elo
The blades on the drum eo, are so arranged that when the pointer d¹º, first comes
over the drum it will be acted upon by eleven blades or produce eleven counts on the
indicator'in one rotation of the drum, and each further step of the pointer along the
drum will cause it to be acted upon by an additional blade and thus produce one more
count at each rotation of the drum.

page_text: In practice a wire a10 which is sensitive to the current required for ten lamps will
respond to successive increments in the current sufficient for supplying single
additional lamps up to the amount sufficient for twenty five lamps, and if a current for.
a larger number of lamps is to be measured in the same circuit it would be necessary
to use a third wire and switch, standing in the same relation to the wire a", that the
wire alo, and switch D,,stand to the wire a.
There are, however, practical objections to the plan of using several sensitive devices
of different conductivity and when there are larger currents than can be measured
directly by a meter having two sensitive devices such as just described, the plan of
dividing them into separate sets and averaging as it were, the indications for the
different sets, is adopted in accordance with this invention; that is, instead of indi-
cating for each set during the whole time of operation, the indications for each set are
taken for a fraction of the time dependent on the number of sets, and the sum of all
the indications are given.
To accomplish this result all the lamps for which a given metre is to indicate are
divided into separate sets each set supplied by the different branches, 4, 5; 6, 7; etc.;
from the main leads; as previously stated, and the metre is introduced into the said
branches one after another by operating the switches C, at definite intervals of time so
that the total indication of the metre during a period equal to the sum of all the
intervals, will represent the number of lamps in operation in all the branch circuits
collectively during that period.
In order to accomplish this result the mechanism shown in figures 6 to 10 inclusive
may be employed to operate the circuit closers G and the counting apparatus e,
e10 B.
The switches C are shown in this instance as operated one after another by means
of a shaft E, extending beneath the said switches as best shown in figure 8 said shaft
being provided with cams or projections E' spaced about it according to the number of
switches to be operated.
The said switches C are shown as levers pivoted at C, and provided at their ends
with contact strips C³, C' cooperating with troughs C, C, containing mercury and
being connected with the wires 12, 13, respectively.
The levers (3, are insulated from one another and the contact strips C³, C+, are so
proportioned that in the normal or horizontal position in which the levers are held by
being weighted at one end as shown at C or by equivalent means, the contact C³, dip
into the mercury in the trough C, thus connecting the levers with the wire 12, and
placing the terminals of the corresponding branches in direct connection through said
wire 12 with the main lead 2 as shown in figure 1.
That one of the levers C however, which is tilted or has its weighted end raised by
the corresponding projection E2, on the shaft E, will have the contact C³ raised from
the mercury cup C, and the other contact C, immersed in the mercury cup Co, thus
connecting that particular branch with the main lead 2, through the wire 13 and
sensitive part of the metre as before stated.
The connection between the levers and the terminals 5, 7, 9, 11, of the branches
may be made by connecting said terminals with separate mercury cups C1, C17, etc.
in which arms or projections C20, from said levers are immersed remaining in the
mercury in both positions of the lever.
As it requires a short time, or from half a minute to a minute in practice, for the
wires a, al, of the sensitive part of the meter to come to the temperature due to the
amount of current flowing, the counting drums e, elo, should not move immediately
after one of the switches c has been moved to place the meter in a given branch-
circuit, and consequently the clock work should be so constructed as to give the
counting drums an intermittent movement.
The apparatus herein shown for the purpose of illustration is capable of metering
for one hundred lamps, which is probably the greatest capacity that will ever be.
required, and in such an apparatus the shaft. E, may be made to turn once in six
minutes thus keeping each of the branch circuits in connection with the meter for a
period of about a minute and a half during each six minutes.

page_text: The drums e, e10, should then be so actuated as to remain stationary during the
first minute after a switch has been shifted, during which time the sensitive part of
the meter will have acquired a condition corresponding to the quantity of current
then flowing in said circuit, and then during the last half minute of said period the
drum should be turned once around and thus count off a number on the counter
which, will correspond to the number of lamps that are in use in said circuit during
the said period of a minute and a half.
e,
The actuating part of the clock or motor for giving the shaft E and the shaft e³, of
the drums e10°
see figures 6 and 7 such movements as just described, may be of the
same character as that already described in connection with figures 1 to 5 the shaft E,
making one rotation in the desired period, in this instance six minutes.
The drum shaft e will have to be rotated four times in this period and this
rotation should be intermittent for the reason before stated.
This is accomplished by causing the gear E³ to mesh with a gear E4, having one
fourth the number of teeth that the gear E³, has, so that the shaft E³, of said gear E*,
turns four times during one rotation of the shaft E.
The four intermittent rotations of the shaft e³, are then effected by a segmental
gear, turning with the shaft E5, (that is four times to each rotation of the shaft E)
said gear in this instance having about one third of its periphery teethed and meshing
with a pinion, having on its entire periphery the proper number of teeth to
cooperate with those of the segment ", so that the said segment ³, which is fixed on.
the drum shaft 3 makes a complete rotation during one third of the time of rotation
of the parts E, E5, and r, and then remains stationary during the other two-thirds of
the rotation of said parts.
Interlocking discs t, t, see Figures 6 and 9 may be employed to bring the drums
to exactly the same point after each rotation and prevent movement of said drums
except when properly acted upon by the gearing r, 112.
With the parts proportioned as described one count on the meter represents one
lamp operating for six minutes and ten counts represents a lamp hour, and the
pointers are gearing of the counting mechanism may be of the usual arrangement,
the first pointer being rotated once around by ten counts and thus indicating fractions
of a single lamp hour, by its position on the dial, while each succeeding pointer
moves one-tenth as fast and thus indicates units, tens, hundreds etc of lamp hours in
the usual manner, as will be understood from Figures 1 and 8.
The operation is as follows.
Assuming that five lamps are burning in branch circuit 4, fifteen in the
circuit, 6, 7, none in the circuit 8, 9, and ten in the circuit 10, 11. Then during
the first period of six minutes the circuit 4, 5 will be placed by the corresponding
switch Cin connection with wire 18 and the sensitive part of the meter, for a period
of one minute and a half and the pointer d during the first minute is thus brought
into position to be acted upon by five blades of the drum e after which during the
last half minute of said period the drum shaft e³ will make a complete rotation causing
five lateral movements of the pointer d which will add five counts on the counting
mechanism.
The other three branches will during this minute and a half be receiving their
current directly through the wire 12 and at the end of the first minute and a half the
first switch C will restore the branch 4, 5, into connection with the wire 12 and the
next switch C will be operated to place the branch 6, 7, in connection with the wire 13,
and sensitive part of the meter which will then receive the current for fifteen lamps
so that before a minute has elapsed the wires a, a¹0 will have been heated sufficiently
to first cause the pointer d to move wholly across the drum e and at the same time to
cause the pointer do, to move far enough to throw the switch D and shunt the wire a,
permitting it to cool and the pointer d to move back to the position where it will not
be engaged by any of the blades, while the pointer do will have been moved forward
to the position to be engaged by fifteen blades on the drum do which after the
minute has elapsed will make a complete rotation causing fifteen lateral movements
of the pointer to and adding fifteen to the count on the indicating mechanism.

page_text: A similar operation will then be repeated for the next branch circuit so that at the
end of the period of six minutes there will have been added to the count a number
equal to the total number of lamps burning in all the branch circuits during the said
period of six minutes and if no change is made in the number of lamps during the
said six minutes the indication will be absolutely correct.
Any errors in the counting arising from changes in the number of lamps in
operation Juring a given period of six minutes will in a considerable period of time
balance so as to produce no appreciable incorrectness, and if necessary the period
occupied by a cycle of the clock movement or rotation of the shaft E may be
lengthened, and various changes in the construction of the mechanical parts or in the
time relations may be made.
When desired to meter the time of operation of instruments that do not vary the
quantity of current used, as for example electric translating devices, arranged in
series, so that the potential and not the quantity of the current is varied as they are
thrown into and out of operation; or instruments that are not operated by electricity
at all, the arrangement shown in Figures 11 and 12 may be adopted.
The meter is shown in Figure 11 as intended to indicate the aggregate of the
product of the number of lamps burning into the length of time that each is burning,
for a number or set of are lamps indicated at T arranged in series in a main circuit
the terminals of which with relation to the series of lamps and entire measuring
apparatus are indicated at 20 and 30.
Any set of arc lamps for which it is desired to measure the lamp hours of
operation are usually grouped together, being for example located in one building or
in a yard or collection of buildings and in order to measure the total number of lamp
hours of operation of the entire set, an auxiliary or meter circuit 41, 51, 61, is
arranged to pass in proximity to all the lamps.
At each of the lamps, the said meter circuit 41, 51, 61 contains a definite amount
of resistance R and a switch S by which the terminals of said resistance may be
connected directly together so as to shunt the same or remove it from the
circuit 41, 51, 61 or the said short connection between the terminals may be
removed so that the resistance is included in the meter circuit.
The said switch S is mechanically connected with or forms a part of the starting and
stopping device $2 by which the lamps or other devices the time of operation of which
is to be measured, are thrown into and out of operation, the said starting device being
in this case a switch which according to its position does or does not make a direct
connection between the terminals of the lamp outside the carbons so as to shunt the
said carbons or to throw them into circuit; and as shown in this instance the connected
switch S and starting device S2, is so arranged that when the lamp is in operation the
resistance R is out of the meter circuit, and when the lamp is out of operation the
resistance is included in the meter circuit; but it is obvious that this arrangement may
be reversed, it being necessary only to make a definite change in the condition of the
meter circuit whenever any one lamp is thrown into operation and to make the reverse
change of condition when a lamp is thrown out of operation, and as the resistance is
the same at each lamp it follows that successive equal increments or decrements are
made in the amount of resistance, as the several switches are operated, it making no
difference in what order the said switches are operated.
For convenience the apparatus the time of operation of which is to be measured,
will hereinafter be spoken of merely as a lamp, but it is obvious that any other instru-
ment or machine might be substituted such for example as an electro motor or in
fact a mechanical motor or a mechanically operated machine, it being necessary only
that the switch S should be connected with or under control of the switch, clutch, belt-
shipper, valve, handle, or starting and stopping device whatever it may be, by which
each machine or instrument is thrown into and out of operation.
It is obvious that the circuit 41 51 61 might be a closed circuit including a battery
or other means for generating a substantially constant E M F, so that the current in
said circuit would vary as the resistance in said circuit was varied by cutting out and
in the different resistances R and consequently any form of current meter included in

page_text: said circuit would indicate or register different amounts of current in a period of time
depending on the aggregate length of time that the several resistances R were in or
out of circuit; and this portion of the invention is not limited to any one specific form
of electric meter to register or indicate the condition of the meter circuit, nor to any
one specific way of supplying the current to said circuit but consists in the employ-
ment in connection with the lamps or other machines of an auxiliary or measuring
circuit and means at each of said lamps or machines for varying the current in said
circuit, controlled by the starting and stopping of said lamp or machine and thus
affording means for making measurement of the time of operation of said lamp or
machine.
When employed for indicating for arc lamps it is probably best to use a meter
substantially the same as hereinbefore described, as indicated in the diagram the
sensitive wire a, of which is in a shunt relative to the circuit 41, 51, 61.
The circuits are then as follows:
:-
The main circuit entering at 20 divides at the point 70, one branch including the
resistance R, and the other branch including the clock magnet k and circuit closer n,
t, controlling the said branch containing the magnet and thus causing the magnet to
be energized intermittently as before described.
Both said branches unite at 80 and the main circuit is continued to the point 41.
where it again branches one portion forming the meter circuit 41, 51, 61, and the other
portion including the wire a, of the meter proper.
These two branches unite at the point 61 from which the main circuits extends
through the lamps T, in series with one another.
The measuring apparatus is in two parallel branches of the main circuit and does
not materially increase the resistance of the main circuit and does not withdraw any
of the current from the lamps T².
The sensitive part a of the meter being in multiple are with the meter circuit 41,
51, 61, it follows that the more resistance there is in the said meter circuit the larger
portion of current will have to pass through the sensitive device and as the resistance
is removed from the meter circuit the current will be withdrawn from the sensitive
part of the meter itself.
As the resistance is removed from the meter circuit when the lights are thrown into
operation it follows that the sensitive part of the meter receives the maximum current
when the fewest lights are in operation or in fact when all the lights are extinguished
and receives the minimum current when all the lights are in operation, and con-
sequently in order that the counting apparatus shall represent the product of the
number of lights burning into the time of burning, the pointer & will have to make the
greatest number of vibrations when the sensitive part a, receives the least current and
the reverse and the blades e', of the drum e are properly disposed to produce such
movements.
The reason for this inversion, that is of making the sensitive part of the meter
receive the least current when it is to give the largest indication is as follows:
With the amount of current commonly employed in the meter the latter is in its
most sensitive condition when the greatest amount of current is passing through it and
will thus respond more readily to an increment or decrement in a current of large
amount than to the same increment or decrement in a current of small amount.
The resistance of the meter circuit 41, 51, 61, outside the resistance R, is small, and
is of course constant and for the purpose of illustration it may be assumed that the
resistance of that circuit is directly proportional to the number of resistances R, that
may be in circuit at any given time.
As such resistances must necessarily be equal in order that the indications may be
the same whichever ones of the entire series of lamps may be in operation, it follows
that when all ten resistances are in circuit the removal of one will make a change
amounting only to one tenth of the current then flowing through said circuit while if
all the resistances but two were cut out the removal of one of these would make a
change equal to one half the current at that time flowing.
That is, the changes become relatively greater the fewer the number of resistances

page_text: in circuit, and as the relative change is smallest when all the resistances are in circuit,
it follows that the meter should be at its most sensitive condition at such time a result
which is attained by having the greatest amount of current passed through the sensitive
part of the meter at such time.
The operation of the apparatus is as follows:-
Assuming that the drum e, turns once in six minutes or ten times an hour, then ten
counts on the indicator will represent one lamp hour it making no difference whether
ten lamps were burned for six minutes, five lamps for ten minutes, or a single lamp
for the whole hour, and so on. Assuming that the current is applied to the main leads
20, 30, but that all the lamps Ts, are cut out, then all the resistance R, will be included
in the meter circuit and the wire a will receive the maximum current and will expand
the maximum amount carrying the pointer d, so that its end is beyond the right hand
of the drum, or at least beyond the end of the longest blade of the drum e, so that the
said drum will rotate without any of its blades and engaging the pointer which will
thus make no lateral movements and will not affect the counting apparatus..
If now one lamp is set in operation the corresponding resistance R will be cut out
of the meter circuit so that a larger portion of the current will pass through the
meter circuit, and the wire a, will receive about one tenth less current than before.
The said wire will therefore contract and the pointer move to that point over the
right hand end of the drum at which it will be engaged by the longest blade once at
each rotation of the drum e thus making one count for every six minutes, ten such
counts representing a lamp hour as before stated.
If another lamp be now thrown into circuit another portion of the resistance will
be cut out and the current again reduced in the wire a moving the pointer d, one step
further to the left so that now it will be struck by two blades at each rotation of the
drum e, adding two on the counting apparatus at each rotation of the druin, and so on
until finally when all the lamps are in circuit and all the resistance removed, from the
meter circuit, the wire a will receive only a small portion of the current, will be but
slightly expanded and the pointer will be in such position near the left hand end of
the drum as to be struck by all of the blades at each rotation thus adding ten to the
count every six minutes.
The indicator or the counting apparatus will thus show a number which will either
represent directly the number of lamp hours that the entire lamps of the series
have been used, or will be a number from which the lamp hours can be readily
computated.
The blades of the drum may be properly set to correspond to the several step
advances of the pointer produced by the successive changes in current as such step
advances are not necessarily of uniform length it is not essential that the current
flowing through the meter should be varied by the introduction and removal of resist-
ance as any other means for adding to or decreasing the quantity of current passing
through sensitive part of the meter might be employed.
As represented in Figure 12 the meter circuit and meter are employed for indicating
the time of operation of apparatus which is not in any way affected by the current
that operates in the meter circuit.
In the construction there illustrated the sensitive part a, of the meter, is included in
circuit between main leads or conductors 45, 65, which extend in proximity to the
apparatus or machines the time of operation of which is to be measured, at each of
which is a branch by which a battery G or equivalent source of electricity may be
thrown into or out of circuit between the main leads, the switch S10 for throwing said
batteries into and out of circuit being connected with or forming part of the starting
and stopping device S20 shown in this instance as a clutch shipper that controls the
operation of the machine.
The sources of electric current are thus placed in multiple arc in the circuit. of the
meter so that the quantity of current passing through the meter varies with the
number of machines in operation in this case increasing as the said number increases,
and the reverse.
.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondent I declare that what I claim is :-
First. An electric meter substantially as herein shown and described.
Second. An electric current indicator composed of two substantially similar and
equal wires one only of which is traversed by the current the strength of which is to
be indicated, and a part connected with said wires and moved by the expansion of one
relatively to the other, substantially as described.
Third. An electric current indicator composed of two substantially similar and
equal wires cach made fast at one end and one forming a part of the circuit for the
current to be measured, combined with a lever connected with the opposite ends of
said wires, and a tension device connected with the said lever which is provided with a
pointer that is moved by the contraction or expansion of one of said wires
relatively to the other substantially as described.
Fourth. A current measurer comprising a pointer moved to different positions by
currents of different quantity combined with an indicating train and an actuator
having a uniform time movement and cooperating with said pointer to give the same
indefinite periods of time a number of movements proportional to the quantity of
current indicated by said pointer which actuates the said indicating train by said
movement substantially as described.
Fifth. The combination of a pointer moved to different positions for currents of
different quantity with a train of wheel work and actuating magnet therefor and
circuit closer for said magnet operated by said pointer in going to and leaving its zero
position and a time measuring regulator actuated by said magnet, and spring con-
necting same with said train of wheel work and a circuit closer for said actuating
magnet controlled by said time regulator for opening and closing the circuit of said
magnet, at definite periods of time, substantially as described.
Sixth. The combination of several circuits each adapted to supply a number of
translating devices arranged in multiple arc in said circuits, with a current meter and
electric switches or circuit changers, co-operating with said circuits and an actuating
time motor therefor, whereby the sensitive part of said meter is placed in one of said
circuits after another during definite intervals of time, substantially as and for the
purpose described.
Seventh. An electric meter comprising two conductors for the current to be
measured, connected in series and one of greater conductivity than the other combined
with a switch or circuit changer and a shunt or branch of low resistance around the
conductor of lower conductivity controlled thereby, said switch being operated to close
the shunt by the conductor of higher conductivity when the current reaches or is above
a predetermined amount, substantially as and for the purpose described.
Dated this 1911
1000
HASELTINE, LAKE & Co..
45, Southampton Buildings, London, Agents for the Applicant.