Improvements in Electric Recording Meters, and in Motors for Operating same.
Year: 1895

page_text: Date of Application, 29th Jan., 1895
Complete Specification Left, 27th Sept., 1895-Accepted, 14th Dec.,
1895
PROVISIONAL SPECIFICATION.
Improvements in Electric Recording Meters, and in Motors for
Operating same.
I, BENJAMIN JOSEPH BARNARD MILLS of 23 Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention, a
communication to me from Charles Wirt, of 904 Walnut Street, Philadelphia, in
the County of Philadelphia, and State of Pennsylvania, in the United States of
America, Electrical Engineer, to be as follows:-
The object of the invention is to produce a simple and efficient meter
for recording the electric current by means of a dial indicator. This is
accomplished by employing a chrono-electric motor for operating a register train,
and which motor will have a definite rate of movement capable of accurate
regulation and adjustment, and which will, at the same time, be simple in.
construction and hence not liable to derangement.
The elements of this motor comprise a pivoted pendulous arm carrying solenoid
cores which co-operate with a stationary solenoid coil.
The pendulum includes suitable adjustable counter-weights which over-balance
the cores and keep such cores normally retracted from the solenoid coil.
In the operation of the chrono-electric motor, it is essential that the current to
the solenoid coil be alternately opened and closed to produce a constant and
uniform swinging of the pendulum. The opening and closing of the circuit to the
solenoid is accomplished by providing the pendulum with a suitable contact piece
adapted to make contact with a floating contact moving freely in one direction and
retarded in the opposite direction. A dash pot, for instance, may be provided for
retarding the movement of the floating contact. The circuit to the solenoid coil
of the motor passes through the floating contact and the pendulum contact, and the
effect is to draw the cores carried by the pendulum into the solenoid coil, thus swinging
the pendulum, which throws the pendulum contact upward, carrying with it the floating
contact. On the return movement of the pendulum, the pendulum contact leaves
the floating contact, breaking the circuit to the solenoid coil and permitting the
pendulum to swing in the opposite direction to the end of its movement without
retardation from the solenoid coil. The pendulum and floating contacts do not meet
again until in the second forward motion of the pendulum, the pendulum contact
reaches the point to which the floating contact has meanwhile fallen, when the
circuit to the solenoid coil is again closed and another impulse given to the
pendulum.
This action of the motor may be modified and regulated by employing a cut off
device for closing a shunt circuit around the motor coil. This cut off device consists
of an adjustable cam-shaped contact plate and a contact carried by the pendulum
adapted to make contact with the cam-shaped plate.
The cam-shaped plate may be adjusted by hand or automatically, according to
how the motor is employed. The contact carried by the pendulum is flexibly
secured so that when said contact strikes the cam-shaped plate the pendulum will
not be suddenly stopped; thus shock or hammering due to the sudden arresting of
the pendulum is avoided. The supply of current to the motor coil will be first cut
off by the separation of the pendulum and floating contacts. The shunt circuit
around the motor coil being closed when this separation occurs the motor coil will

page_text: discharge through that circuit and no sparking will occur when the pendulum and
floating contacts separate.
In electric meters, the cut off for the motor is adjusted and controlled by a
current indicator. This indicator may be one having a solenoid coil and a core
carried by a shaft on which the cam-shaped plate is mounted. In practice the
contact designed to strike the cam plate will be rigidly secured upon a disc which
is mounted on the shaft which actuates the register train, and the disc will be
flexibly connected with the pendulum. The cam plate controlled by the current
indicator will be formed, with reference to the movements of the indicator
produced by variations in the current flowing through the solenoid coil of the
indicator, so that the disc referred to will be permitted to move at each oscillation of
the penduluin an angular distance corresponding accurately with the variations in
current in the solenoid coils of the indicator.
Hence when the contact carried by this disc strikes the cam plate, not only will
the shunt circuit around the motor coil be closed, but the driving shaft of the
register train will be positively arrested. Thus the register train is intermittently
driven a distance proportional to the current flowing through the solenoid coil of
the indicator. The flexible connection between the motor and the disc on the
driving shaft of the register permits a further movement of the pendulum after the
disc is arrested, whereby shock or hammering is avoided, as before stated.
In an electric meter the current indicator is placed in the line of the main
conductors and the motor is connected between the main conductors, or, in other
words, in a multiple arc circuit.
In addition to the general features of novely thus indicated, my meter also
possesses other features of novelty in the details of its construction which will
appear from the specific description of the apparatus.
On the base of the instrument are mounted two solenoid coils formed upon the
are of a circle.
These solenoid coils act upon soft iron wire cores, which are carried by a shaft
having suitable counterbalancing weights.
This device is an approved form of current indicator. The two coils are
provided so that the meter may be used for a 3-wire circuit as well as for a 2-wire
circuit.
In the former case, the coils are connected one in the line of one of the
outside main conductors, and the other in the line of the other of the outside main
conductors; in the latter case the two coils may be joined in multiple in the line
of one of the main conductors, but the preferred way would be to connect one coil
in each of the main conductors.
In order to make the current indicator less liable to inaccuracies by reason of
friction, I mount the ends of the shaft carrying the soft iron wire cores, upon
rocking bars which rise from the base of the machine, where they are connected
by a rod which lies in a metal trough mounted upon an insulating block. The
reduced ends of the core carrying shaft rest upon the upper ends of these rocking
bars which are confined in their movement by plates which also prevent the
dislodgement of the shaft. The plates are mounted upon suitable posts, from
which they are insulated.
A cross-bar of insulating material is provided to prevent the wire cores from
striking the metal end pieces of the solenoids. The core carrying shaft, the
supporting rocking arms and the retaining plates are therefore insulated from the
base and from other parts of the apparatus. The rocking arms form an exceedingly
effective anti-friction bearing for the core carrying shaft since, as the shaft turus,
it rolls on the upper ends of these arms and the arms rock back and forth. Owing
to their length, the movement at the pivot of the arms is exceedingly slight and
consequently the friction is reduced to a minimum. Instead of having the rocking
arins rising from the base of the machine, the plates may be extended upwardly
and carry triangular links, which are pivoted at the upper ends of the extended
plates and receive the ends of the core carrying shaft at the lower ends. This

page_text: construction is simply a reversal of that above described, the triangles being rocking
bars having a long leverage on the friction at their pivots and having the minimum
movement at such pivots, as in the case of the rocking arms.
The chrono-electric motor is mounted upon the base adjoining the current
indicator.
The elements of this motor comprise a pivoted pendulous arm carrying solenoid
cores which co-operate with a stationary solenoid coil mounted upon a block rising
from the base.
The pendulum includes suitable adjustable counter-weights which overbalance
the cores and keep such cores normally retracted from the solenoid coil. The
pendulum is mounted upon a sleeve which is carried by a shaft.
The pendulum contact projects from the inner end of the sleeve and engages
with the floating contact. This floating contact is a finger pivoted upon an
upright and having a counter-weight which slightly overbalances the finger and
tends to throw it upwardly.
A thread connects the finger with a weight which works in a dash-pot. This
dash-pot is surrounded by a protecting casing and carries in its bottom an
inwardly opening valve. The weight also constitutes the dash-pot plunger. It
has a free upward movement because the valve admits air beneath it, but its
downward movement is retarded by the closing of the valve. The dash-pot weight
is sufficiently heavy when raised to pull down the floating contact finger in its
downward retarded movement.
The circuit of the chrono-electric motor (which will be more fully hereinafter
set forth) passes through the floating contact and the pendulum contact and also
through the solenoid coil. The effect is to draw the cores into the solenoid, thus
Swinging the pendulum and turning the sleeve which throws upwardly the
pendulum contact carrying with it the floating contact. On the return movement
of the pendulum, the pendulum contact leaves the floating contact, breaking the
circuit to the solenoid and permitting the pendulum to swing in the opposite
direction to the end of its movement, the contacts not meeting again until in the
second forward movement of the pendulum the contact reaches the point to which
the floating contact has in the meantime fallen, when the circuit of the solenoid is
again closed and another impulse given to the pendulum. The sleeve turns on
rocking bars which are connected together at their lower ends by a rod resting in a
metal trough and supported by a block of insulating material. The rocking arms
and the sleeve are limited in their movement by plates which are supported upon
and insulated from suitable posts. These parts correspond precisely with the
similar parts which support the shaft of the current indicator and form an effective
anti-friction bearing for the rocking sleeve. The pendulum and the parts carried
by the sleeve and shaft are insulated from the other parts of the machine, and it
should also be said that the upright carrying the floating contact the dash-pot and
the surrounding casing are also insulated from the standard which supports them in
order to give proper direction to the current. Instead of the rocking bars the
sleeve may be hung from suspended rocking bars, the same as in the case of the
rocking bars which support the shaft of the current indicator. On the inner end
of the pendulum carrying shaft is rigidly secured a disc to which is attached a leaf
spring and beneath the leaf spring is a stud projecting from the same arm which
carries the pendulum contact. By means of the leaf spring and stud, the sleeve
and pendulum carrying shaft are flexibly connected together, so that the rocking
movement of the sleeve which it receives from the pendulum, will be communicated
to the shaft until such shaft is positively arrested by the means which will be
presently described, when the spring permits a further movement of the sleeve and
the pendulum carried by it, without the shock or hammering due to the sudden
arresting of these heavier parts.
Upon the inner end of the core carrying shaft of the current indicator is
mounted a cam which projects upwardly and has a curved outer end located close to
the disc on the inner end of the pendulum carrying shaft. This cam is the cutoff

page_text: $
cam of the chrono-electric motor, and it is adjusted by the movements of the
current indicator. The disc carrying the leaf spring has a stud, which in the
forward movement of the pendulum strikes the rim of the cam, which rim is
formed, with reference to the movements of the current indicator produced by
variations in the current flowing through the solenoids, so that the disc will be
permitted to move at each oscillation of the pendulum an angular distance
corresponding accurately with the variations in current in the solenoids.
Rigidly attached to the outer end of the shaft is a crank-arm carrying on its end
a small block of insulating material. This crank-arm, as a means of procuring a fine
adjustment, is made somewhat flexible and is located parallel with a rigid arm through.
which a screw passes and impinges against the crank-arm so as to vary the distance
between the arms. In the movement of the pendulum carrying shaft the insulated
end of the crank-arm strikes a clutch arm which, through a friction clutch operating
like a pawl and ratchet, turns a wheel, which wheel is on the first shaft of a register
train, such register train being of any usual or suitable construction and being
mounted in suitable front and back plates. The crank-arm, which operates the
register, being rigidly connected to the pendulum carrying shaft, has a movement
which is definitely determined by the striking of the stud on the limiting segment,
although the pendulum may have a still greater movement permitted by the spring.
If the oscillating motor is in operation and no current is passing through the
indicator coils, the cam will not permit a sufficiently great forward movement of
the disc carrying the leaf spring to cause the crank to move the clutch. When
however, any current flows through the indicator coils, the segment will be moved
30 as to permit the disc to have a greater movement, and the crank will also have
a greater movement and will move the clutch-arm thus imparting an intermittent
movement to the register train. It will be understood that the striking of the pin
against the rim of the cam, not only mechanically arrests the crank-arm, but also
at the same time short circuits the motor coil, thus withdrawing the current from
the motor coil and permitting the pendulum to start back freely without retardation
from the motor coil. The additional movement which the pendulum has by reason
of the flexible connection of sleeve with disc, causes it to break the motor circuit
at the floating contact on the backward swing of the pendulum before the shunt is
broken by the separation between the stud and the segment. The supply of
current will be first cut off from the motor coil by the separation of the pendulum
contact and floating contact. The shunt around the motor coil formed by contact
between segment and stud will still be closed and the coil will discharge through
this shunt and no sparking will occur when these parts separate. This arrangement
prevents all sparking at the contacts.
In addition to the parts of the apparatus already described, I provide a suitable
resistance composed of one or more rods which are constructed, preferably, of a
composition of powdered carbon with earthy materials so as to have an excessively
high resistance, and are connected in circuit by suitable metal clamps. The motor
coil it should also be understood, is made of a great length of fine wire and has a
high resistance, since the motor is designed to be continuously in circuit and to
operate with the expenditure of a minimum quantity of current. On the other
hand the indicator coils are made of a relatively few turns of coarse wire, since
those coils are designed to be placed directly in the main circuit.
The circuit connections when the meter is constructed for and used upon a
simple 2-wire multiple are circuit and has only one indicator coil is as follows:
To the main conductors are connected the lamps or other translating devices. The
coil is introduced directly in the circuit of the conductor 1. The other parts of
the meter are introduced into a multiple arc circuit between the conductors 1
and 2, which circuit consists of a wire extending from the main conductor 2 to the
floating contact; also a wire extending from the disc carrying the leaf spring to
one end of the motor solenoid; also a wire extending from the other end of the
motor solenoid to the lower end of the resistance rod; and finally of a wire
extending from the upper end of the resistance rod to the main conductor, 1.

page_text: A shunt around the motor solenoid is formed by a wire extending from the
segment to the lower end of the resistance rod. When the lamps are cut out, there
is no current flowing through the current indicator and the cam is then in its normal
position. The circuit to the motor coil however, is closed, and the motor pendulum
is free to oscillate, but the arc of vibration will not be sufficient to permit of its
driving the registering train, as before explained.
.
The circuit connections when a meter constructed for a 3-wire system is used on
a 2-wire system are exactly like those of the 2-wire system except that the extra
indicator coil is placed in the line of the main conductor 2.
The circuit connections of a meter for a 3-wire system, are like those just
described except that the multiple arc circuit in which the motor is placed, is
connected between the neutral wire of the 3-wire system and the outside main
conductor 1.
It will thus be seen that the oscillating motor is always in circuit and is running,
but that the register is not operated except when there is current flowing through
the indicator coils. Since the current flowing through the indicator coils will be
precisely proportional to the amount used in the lamps or other translating devices,
and since the cam permits the oscillating shaft to move an angular distance
corresponding accurately to the amount of current in the indicator coils, that
oscillating shaft will move the register through the crank-arm and clutch at each
oscillation of the motor a distance corresponding to the quantity of current flowing
through the indicator coils and the register will show at its dials the quantity of
current used. The current indicator is free to adjust the segment at all times
except when the stud is pressing against that segment, and hence its position
will be an accurate indication at every moment of the amount of current which is
being used.
Dated To 20th 100
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.
Improvements in Electric Recording Meters, and in Motors for
Operating same.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23 Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Charles Wirt, of 904 Walnut Street, Philadelphia,
in the County of Philadelphia and State of Pennsylvania, U.S.A., Electrical
Engineer,) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
The object of the invention is to produce a simple, and efficient meter for
recording the electric current by means of a dial indicator. This is accomplished
by employing a chrono-electric motor for operating a register train, and which
motor will have a definite rate of movement capable of accurate regulation and
adjustment, and which will, at the same time, be simple in construction and hence
not liable to derangement. The elements of this motor comprise a pivoted
pendulous arm carrying solenoid cores which cooperate with a stationary solenoid
coil. The pendulum includes suitable adjustable counter weights which over-
balance the cores and keep such cores normally retracted from the solenoid coil.
In the operation of the chrono-electric motor, it is essential that the current to
the solenoid coil be alternately opened and closed to produce a constant and
uniform swinging of the pendulum. The opening and closing of the circuit to the
solenoid is accomplished by providing the pendulum with a suitable contact piece
adapted to make contact with a floating contact moving freely in one direction and

page_text: retarded in the opposite direction. A dash-pot, for instance, may be provided for
retarding the movement of the floating contact. The circuit to the solenoid coil
of the motor passes through the floating contact and the pendulum contact, and the
effect is to draw the cores carried by the pendulum into the solenoid coil, thus
swinging the pendulum, which throws the pendulum contact upward, carrying with
it the floating contact. On the return movement of the pendulum, the pendulum
contact leaves the floating contact, breaking the circuit to the solenoid coil and
permitting the pendulum to swing in the opposite direction to the end of its
movement without retardation from the solenoid coil. The pendulum and floating
contacts do not meet again until in the second forward movement of the pendulum,
the pendulum contact reaches the point to which the floating contact has meanwhile
fallen, when the circuit to the solenoid coil is again closed and another impulse
given to the pendulum.
This action of the motor may be modified and regulated by employing a cut-off
device for closing a shunt circuit around the motor coil. This cut-off device
consists of an adjustable cam shaped contact plate and a contact carried by the
pendulum adapted to make contact with the cam shaped plate. The cam shaped
plate may be adjusted by hand or automatically, according to how the motor is
employed. The contact carried by the pendulum is flexibly secured so that when
said contact strikes the cam shaped plate the pendulum will not be suddenly
stopped; thus shock or hammering due to the sudden arresting of the pendulum is
avoided. The supply of current to the motor coil will be first cut off by the
separation of the pendulum and floating contacts. The shunt circuit around the
motor coil being closed when this separation occurs the motor coil will discharge
through that circuit and no sparking will occur when the pendulum and floating
contacts separate.
In electric meters, the cut-off for the motor is adjusted and controlled by a
current indicator. This indicator may be one having a solenoid coil and a core
carried by a shaft on which the cam shaped plate is mounted. In practice the
contact designed to strike the cam plate will be rigidly secured upon a disc which
is mounted on the shaft which actuates the register train, and the disc will be
flexibly connected with the pendulum. The cam plate controlled by the current
indicator will be formed, with reference to the movements of the indicator produced
by variations in the current flowing through the solenoid coil of the indicator, so
that the disc referred to will be permitted to move at each oscillation of the
pendulum an angular distance corresponding accurately with the variations in
current in the solenoid coils of the indicator. Hence when the contact carried by
this disc strikes the cam plate, not only will the shunt circuit around the motor
coil be closed, but the driving shaft of the register train will be positively arrested.
Thus the register train is intermittently driven a distance proportional to the
current flowing through the solenoid coil of the indicator. The flexible connection
between the motor and the disc on the driving shaft of the register permits a
further movement of the pendulum after the disc is arrested, whereby shock or
hammering is avoided, as before stated.
In an electric meter the current indicator is placed in the line of the main
conductors and the motor is connected between the main conductors, or, in other
words, in a multiple are circuit.
In addition to the general features of novelty thus indicated, the improved meter
also possesses other features of novelty in the details of its construction which will
appear from the specific description of the apparatus.
In the accompanying drawings forming a part hereof,
Fig. 1 is a perspective view of a meter embodying the invention.
Fig. 2 is a top view or plan of the same.
Fig. 3 is a vertical section on line 3-3 in Fig. 2.
Fig. 4 is an end elevation of the meter.
Fig. 5 is a sectional view through the retarding dash-pot which controls the
movement of the floating contact of the motor.

page_text: 15 21 perspective
construction.
view
01 a MOUTHICCION OL one ΟΙ the details OF
Fig. 7 is a diagrain of the circuit connections when the meter is constructed for
a two-wire system, and
Figs. 8 and 9 are diagrams of the circuit connections for a two-wire system and
a three-wire system, respectively, when the meter is constructed for use in either
system.
A is the base of the instrument, upon which are mounted two solenoid coils B B
formed upon the arc of a circle. These solenoid coils act upon soft iron wire
cores a a, which are carried by a shaft C having suitable counterbalancing
weights b. This device is an approved form of current indicator. The two coils
are provided so that the meter may be used for a three-wire circuit as well as for
a two-wire circuit. In the former case, the coils are connected one in the line of
one of the outside main conductors, and the other in the line of the other of the
outside main conductors; in the latter case the two coils may be joined in multiple
in the line of one of the main conductors, but the preferred way would be to
connect one coil in each of the main conductors. In order to make the current
indicator less liable to inaccuracies by reason of friction, the ends of the shaft C
carrying the soft iron wire cores a a are mounted upon rocking bars cc, which rise
from the base of the machine, where they are connected by a rod c' which lies in a
metal trough c² mounted upon an insulating block c³. The reduced ends of the
shaft C rest upon the upper ends of these rocking bars c, which are confined in
their movement by plates C', which also prevent the dislodgment of the shaft.
These plates C are mounted upon suitable posts, from which they are insulated.
A cross bar d of insulating material is provided to prevent the wire cores a from
striking the metal end pieces of the solenoids B B. The shaft C, the supporting
rocking arms c, and the retaining plates C₁, are therefore insulated from the base
and from other parts of the apparatus. The rocking arms c c form an exceedingly
effective antifriction bearing for the shaft C, since, as the shaft turns, it rolls on
the upper ends of these arms and the arms rock back and forth. Owing to their
length; the movement at the pivot of the arms is exceedingly slight and conse-
quently the friction is reduced to a minimum. Instead of having the rocking arms
rising from the base of the machine, the plates C¹ may be extended upwardly and
carry triangular links d, which are pivoted at the upper ends of the extended
plates and receive the ends of the shaft C at the lower ends, as shown in Fig. 6.
This construction is simply a reversal of that which is shown in the other figures
of the drawings, the triangles being rocking bars having a long leverage on the
friction at their pivots and having the minimum movement at such pivots, as in the
case of the rocking arms c.
The chrono-electric motor is mounted upon the base A adjoining the current
indicator. The elements of this motor comprise a pivoted pendulous arm D
carrying solenoid cores d which cooperate with a stationary solenoid coil E
mounted upon a block e rising from the base A. The pendulum includes suitable
adjustable counter-weights el which overbalance the cores d² and keep such cores
normally retracted from the solenoid coil E. The pendulum D is mounted upon a
sleeve (Fig. 3) which is carried by a shaft F. The pendulum contact projects
from the inner end of the sleeve F and engages with the floating contact : This
floating contact is a finger pivoted upon an upright f2 and having a counter-
weight which slightly overbalances the finger and tends to throw it upwardly.
A thread connects the finger with a weight (Fig. 5) which works in a
dash-pot G. This dash-pot is surrounded by a protecting casing G₁ and carries in
its bottom an inwardly opening valve gl. The weight g also constitutes the dash-
pot plunger. It has a free upward movement because the valve g¹ admits air
beneath it, but its downward movement is retarded by the closing of the valve g¹.
The dash-pot weight g is sufficiently heavy when raised to pull down the floating
contact finger f' in its downward retarded movement.
The circuit of the chrono-electric motor (which will be more fully hereinafter

page_text: set forth) passes through the floating contact f' and the pendulum contact f, and
also through the solenoid coil E. The effect is to draw the cores into the
solenoid E, thus swinging the pendulum and turning the sleeve F, which throws
upwardly the pendulum contact f, carrying with it the floating contact . On the
return movement of the pendulum, the pendulum contact leaves the floating
contact, breaking the circuit to the solenoid E and permitting the pendulum to
swing in the opposite direction to the end of its movement, the contacts ff not
meeting again until in the second forward movement of the pendulum the contact f
reaches the point to which the floating contact has in the meantime fallen, when
the circuit of the solenoid E is again closed and another impulse given to the
pendulum. The sleeve F turns on rocking bars h, which are connected together
at their lower ends by a rod (Fig. 3) resting in a metal trough 2² and supported
by a block of insulating material h³. The rocking arms h and the sleeve F are
limited in their movement by plates H which are supported upon and insulated
from suitable posts. These parts correspond precisely with the similar parts which
support the shaft of the current indicator and form an effective anti-friction
bearing for the rocking sleeve F. The pendulum and the parts carried by the
sleeve F and shaft Fare insulated from the other parts of the machine, and it
should also be said that the upright f, the dash-pot G and the surrounding
casing G¹ are also insulated from the standard which supports them in order to
give proper direction to the current. Instead of the rocking bars h, the sleeve F
may be hung from suspended rocking bars of the construction illustrated in Fig. 6,
the same as in the case of the rocking bars which support the shaft of the current
indicator. On the inner end of the shaft F' is rigidly secured a disc I, to which
is attached a leaf spring (Figs. 1 and 4), and beneath the leaf spring i is a
stud projecting from the same arm which carries the pendulum contact. By
means of the leaf spring i and stud ¹, the sleeve F and shaft F' are flexibly
connected together, so that the rocking movement of the sleeve F, which it
receives from the pendulum, will be communicated to the shaft F¹ until such shaft
is positively arrested by the means which will be presently described, when the
spring permits a further movement of the sleeve F and the pendulum carried by
it, without the shock or hammering due he sudden arresting of these heavier
parts.
Upon the inner end of the shaft C the current indicator is mounted a cam K
which projects upwardly and has arved outer end located close to the disc I on
the inner end of the pendulum.rrying shaft F'. This cam K is the cut-off' cam
of the chrono-electric motor, id it is adjusted by the movements of the current
indicator. The disc I has a stud k, which in the forward movement of the pendulum
strikes the rim of the cam K, which rim is formed, with reference to the movements
of the current indicator produced by variations in the current flowing through the
solenoids B, so that the disc I will be permitted to move at each oscillation of the
pendulum an angular distance corresponding accurately with the variations in
current in the solenoids B.
Rigidly attached to the outer end of the shaft F is a crank-arm L carrying on
its end a small block of insulating material . This crank-arm, as a means of
procuring a fine adjustment, is made somewhat flexible and is located parallel with
a rigid arm L¹ through which a screw passes and impinges against the crank-
arm L so as to vary the distance between the arms L L'. In the movement of the
shaft F, the insulated end of the crank-arm L strikes a clutch-arın M, which,
through a friction clutch m operating like a pawl and ratchet, turns a wheel m¹,
which wheel is on the first shaft of a register train N, such register train being of
any usual or suitable construction and being mounted in suitable front and back
plates N¹. The crank-arm L, which operates the register, being rigidly connected
to the shaft F¹, has a movement which is definitely determined by the striking of
the stud on the limiting segment K, although the pendulum may have a still
greater movement permitted by the spring i. If the oscillating motor is in
operation and no current is passing through the indicator coils B, the cam K will

page_text: not permit a sufficiently great forward movement of the disc I carrying the leaf
spring to cause the crank L to move the clutch. When, however, any current
flows through the indicator coils B, the segment K will be moved so as to permit
the disc I to have a greater movement, and the crank L will also have a greater
movement and will move the clutch-arm M, thus imparting an intermittent
movement to the register train. It will be understood that the striking of the
pink against the rim of the cam K, not only mechanically arrests the crank-arm,
but also at the same time short circuits the motor coil E, thus withdrawing the
current from the motor coil, and permitting the pendulum to start back freely
without retardation from the motor coil E. The additional movement which the
pendulum has by reason of the flexible connection of sleeve F with disc I,
causes it to break the motor circuit at the floating contact f¹ on the backward
swing of the pendulum before the shunt is broken by the separation between the
stud and the segment K. The supply of current will be first cut off from the
motor coil E by the separation of the pendulum contact fand floating contact f¹.
The shunt around the motor coil E formed by contact between segment K and
stud will still be closed and the coil will discharge through this shunt and no
sparking will occur when these parts K and k separate.
This arrangement
prevents all sparking at the contacts. This will be better understood by reference
to the diagram of the circuits shown in Figs. 7, 8 and 9, which will be presently
described.
In addition to the parts of the apparatus already described, a suitable resistance
is provided composed of one or more rods O, which are constructed preferably
of a composition of powdered carbon with earthy materials so as to have an
excessively high resistance, and are connected in circuit by suitable metal
clamps o. The motor coil E it should also be understood is made of a great
length of fine, wire and has a high resistance, since the motor is designed to be
continuously in circuit and to operate with the expenditure of a minimum quantity
of current. On the other hand, the indicator coils B are made of a relatively few
turns of coarse wire, since those coils are designed to be placed directly in the
main circuit.
Referring now to Fig. 7, this figure illustrates the circuit connections when the
meter is constructed for and used upon a simple two-wire multiple are circuit and
has only one indicator coil B. 1 and 2 are the main conductors, to which are
connected the lamps or other translating devices P. The coil B is introduced
directly in the circuit of the conductor 1. The other parts of the meter
are introduced into a multiple are circuit between the conductors 1 and 2
which circuit consists of a wire 3 extending from the main conductor 2 to the
floating contact f¹; also a wire 4 extending from the disc I, carrying the leaf
spring, to one end of the motor solenoid E; also a wire 5 extending from the
other end of the motor solenoid E to the lower end of the resistance rod 0; and
finally of a wire 6 extending from the upper end of the resistance rod O to the
main conductor 1. A shunt around the motor solenoid E is formed by a wire 7
extending from the segment K to the lower end of the resistance rod O. In this fig.
the lamps Pare cut out and hence there is no current flowing through the current
indicator and the cam K is shown in its normal position. The circuit to the motor
coil E, however, is closed, and the motor pendulum is free to oscillate, but the arc
of vibration will not be sufficient to permit of its driving the registering train, as
before explained.
In Fig. 8, which illustrates the circuit connections when a meter constructed
for a three-wire system is used on a two-wire system, the connections are exactly
like those of Fig. 7, except that the extra indicator coil B is placed in the line of
the main-conductor 2. In this figure the switches to the lamps P are closed, and
the cam K is moved by the current indicator to a position corresponding to the
amount of current flowing through the indicator coils B. The disc I carrying the
leaf spring is shown in the position at which the motor coil E is cut out, that is,
the stud k making contact with the rim of cam K. As before explained, the pendulum.
B

page_text: is capable of forward movement after the stud k strikes the cam K by reason of
the flexible connection between the sleeve F and disc J. In this figure the free end
of the leaf spring i is pulled away from the disc I by stud ¹ which is carried by the
pendulum sleeve F, and in this position the pendulum is about to start on its
backward swing. As the pendulum swings backward, the contacts f and fl
separate before the stud k and cam K separate, since the disc I cannot move
backward with the pendulum until the stud carried by the pendulum sleeve meets
it, and hence sparking at the contacts fand f' is avoided.
In Fig. 9, which illustrates the circuit connections of a meter for a three-wire
system, the connections are like those of Fig. 8, except that the multiple arc
circuit 3, 6, in which the motor is placed, is connected between the neutral wire
of the three-wire system and the outside main conductor 1. In this figure the
cam K is shown.in the same position as in Fig. 8, and the disc I is shown in the
position to which it is carried upon the backward swing of the pendulum D and
just before the pendulum starts on its next forward swing, the contact f and floating
contact being separated. The contact will meet the floating contact f¹ before
the stud k strikes the cut-off cam K, which closes the circuit to the motor coil E
and gives another impulse to the pendulum, as above explained.
The several circuit wires, where they appear in the other figures of the drawings,
bear reference letters corresponding to the reference letters of Figs. 7, 8 and 9.
It will thus be seen that the oscillating motor is always in circuit and is running,
but that the register is not operated except when there is current Howing through
tne indicator coils B. Since the current flowing through the indicator coils B will
be precisely proportional to the amount used in the lamps or other translating
devices, and since the cam K permits the oscillating shaft to move an angular
distance corresponding accurately to the amount of current in the indicator coils B,
that oscillating shaft will move the register, through the crank arm and clutch, at
each oscillation of the motor, a distance corresponding to the quantity of current
flowing through the indicator coils B, and the register will show at its dials the
quantity of current used. The current indicator is free to adjust the segment K
at all times except when the stud k is pressing against that segment, and hence its
position will be an accurate indication at every moment of the amount of current
which is being used.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, declare that what I
claim is :-
1. A chrono-electric motor having in combination a pendulum, a contact moved
thereby, an electric actuating device, and a contact having a retarded movement
towards the pendulum contact and a free movement in the opposite direction,
substantially as and for the purposes set forth.
2. A chrono-electric motor having in combination a pendulum, a contact moved
thereby, an electric actuating device, a contact having a retarded movement
towards the pendulum contact and a free movement in the opposite direction, and
an adjustable cut-out device withdrawing the current from the electric actuating
device at a predetermined point during the closure of the circuit by the pendulum
and retarded contacts, substantially as and for the purposes set forth.
3. A chrono-electric motor having in combination a pendulum, a contact moved
thereby, an electric actuating device, a contact having a retarded movement
towards the pendulum contact and a free movement in the opposite direction, said
retarded contact closing the circuit at the pendulum contact when the parts are
in the position of rest, and an adjustable cut-out device withdrawing the current
from the electric actuating device at a predetermined point during the closure of
the circuit by the pendulum and retarded contacts, substantially as and for the
purposes set forth.
4. In a chrono-electric motor, the combination with the oscillating pendulum,
actuating solenoid and contact baving a retarded movement in one direction, of a

page_text: flexible or yielding contact carried by the pendulum, and an adjustable contact
point or plate closing a shunt or cut-out circuit with the yielding contact at a
predetermined point, substantially as and for the purposes set forth.
5. An electric motor constructed and operating substantially as and in the
manuer set forth and for the purpose stated.
6. In an electric meter, the combination of an oscillating motor for driving a
register, and means controlled by a current indicator for controlling the arc of
vibration of said motor, whereby the movement of the motor is made proportional
to the current to be measured, substantially as set forth.
7. In an electric meter, the combination of an electric oscillating motor for
driving a register, and a cut-off controlled by a current indicator for cutting off
the current to said motor at each oscillation, whereby the arc of vibration is made
proportional to the current to be measured, substantially as set forth.
8. In an electric meter, the combination of an oscillating electric motor, a
register train, a driving device actuated by said motor and adapted to intermittently
drive said register train, a flexible connection between said driving device and
motor, and means controlled by a current indicator for limiting the forward move-
ment of said driving device, whereby each movement of the register train is made
proportional to the current to be measured, substantially as set forth.
9. In an electric meter, the combination with a current indicator and a controlling
cam moved thereby, of a continuously running oscillating electric motor, and a
register train intermittently moved by said motor to an extent regulated at each
movement by said controlling cam, substantially as set forth.
10. In an electric meter, the combination with a current indicator and a con-
trolling cam moved thereby, of an oscillating electric motor, a register train moved
intermittently by said motor to an extent regulated at each movement by the
position of said controlling cam, and a shunt around said electric motor closed by
contact between said controlling cain and the part of the motor which engages
therewith, substantially as set forth.
11. The combination with a current indicator and a controlling cam moved
thereby, of a chrono-electric motor comprising a pendulum, an operating solenoid,
pendulum and floating contacts, and cut-out contacts co-operating with the con-
trolling cam, and a register train moved intermittently by said motor to an extent
regulated at each movement by the position of said controlling cam, substantially
as set forth.
12. An electric meter constructed and operating substantially as and in the
manner set forth.
Dated this 27th day of September 1895.
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.