Improvements in and relating to Electricity Meters
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Electricity Meters
PERCY WILBRAHAM NORTHEY, Electrical Engineer, of 74, Caistor Road, Balham,
in the County of Surrey, and THE ELECTRIC MOTIVE POWER Co. LTD., Motor
Carriage Builders, having Registered Offices at 17, Tower Royal, Cannon Street,
London, do hereby declare the nature of this invention to be as follows:-
Our invention relates to that form of electricity meter known as an ampere-
hour meter and has for its object an improved means whereby the amount of
energy remaining in a battery of accumulators, or other electrical battery can
be ascertained & recorded on a dial, whilst at the same time by a suitable reversing
mechanism automatically actuated by a double-coil relay, all currents which are
opposite in direction to the normal may be credited to the battery.
Many methods are well known by which the work done by a battery in watt-
hours or ampere-hours may be recorded, but hitherto no means have been devised
for ascertaining the amount of electrical work remaining in a battery after a
partial discharge at widely varying rates, as it is found that the capacity of a
battery varies inversely as the rate of discharge.
We also provide means for automatically registering on an unwinding tape or
other device all occasions whenever the discharge rate of current exceeds a given
maximum, & also the length of time over which such heavy rate of discharge has
extended.
Any suitable form of indicator may be provided, such as an electric bell, in
order to give due notice while the heavy discharge lasts. Our instrument is
formed of a combination of an ampere measuring device, operating on a variable
gear interposed between clockwork of a constant velocity, & a recording dial...
A means for enabling tape to be unwound from a drum, & to be indented or
otherwise marked, & a bell or other indicator put in action, at such times as the
current rises above the maximum rate of discharge; a means whereby a belt
shifting arrangement is attached to & worked by the ammeter, dashpots being
employed if necessary to control the action of the ammeter. A means whereby a
reversal of the direction of rotation of the dial is effected by the action of a double
coil relay at such times as the direction of the current is opposite to the normal.
According to our invention we have a registering plate suitably graduated in
terms of miles, which is turned by the driven drum (one of two drums both
suitably tapered) through a convenient reduction of worm & gear wheels.
The driving drum which is placed inversely to the driven drum is worked by
an internal clock, & may be graduated in hours, & drives the second drum by
an endless belt or cord.
The relative position of the driving belt or cord on the drums is regulated
by the armature of the ammeter to which it is attached by means of an endless
belt led round a pulley on the said armature, the attachment being effected by a
clutch composed preferably of four or more wheels, which enables the first men-
tioned belt to revolve without allowing it to alter its position from a given plane

page_text: on the coned drums, unless by the movement of the armature. At such times
as the current is above the maximum rate of discharge the armature of the
ammeter brings into action a suitable tape or other recording device, and at the
same time causes a bell or other indicator to sound & to continue sounding so
long as this rate of discharge, remains above' the maximum. The reversing
mechanism above referred to may preferably consist of a double coil relay form-
ing a local circuit & actuated by a polarized armature which puts in circuit either
one or the other of the two relay coils in accordance with the direction of cur-
rent in the main circuit, thus by means of suitable reversing mechanism causing
the direction of rotation of the drums, & consequently the dial to be reversed.
The instrument is equally suitable for registering the recharging of the battery
for which purpose we construct the driving wheels of the reversing mechanism in
such a way that one direction of speed, namely that which will be operated by
a reversal of the current has less velocity than the other, in order that the cells
may have their sufficiency of overcharge.
1011
1
P
1000
Dated this 10th day of
1300300
1000
PERCY WILBRAHAM NORTHEY, A.I.E.E., Electrical Engineer, and THE ELECTRIC
MOTIVE POWER COMPANY LIMITED, Motor Carriage Builders, both of 74, Caistor
Road, Balham, in the County of Surrey, the latter formerly of 17, Tower Royal,
Cannon Street, London, do herby 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:-
·
Our invention relates to that form of electricity meter known as an ampere-
hour meter and has for its object an improved means whereby the amount of
_energy remaining in a battery of accumulators or other electrical battery can be
"ascertained & recorded on a dial whilst at the same time, by a suitable reversing
mechanism, automatically actuated by a double-coil relay or other equivalent
device all currents which are opposite in direction to the normal, may be credited
to the battery. Many methods are well known by which the work done by a
battery in watt-hours or ampere-hours may be recorded, but hitherto no reliable
means have been devised for ascertaining the amount of electrical work remaining
in a battery after a partial discharge at widely varying rates, as it is found that
the capacity of a battery varies inversely as the rate of discharge. . We also pro-
vide if desired means for automatically registering on an unwinding tape or other
device all occasions when the discharge rate of current is above the maximum &
also the length of time during which this heavy rate of discharge lasts. Any
suitable form of indicator may be provided, such as an electric bell in order to
give due notice while the heavy discharge lasts. Our instrument is formed of a
combination of an ampere measuring device operating on a variable gear, inter-
posed between clockwork of a constant velocity. A means whereby the variable
gear arrangement is attached to & varied by the ammeter, dashpots being em-
ployed if necessary to control the action of the ammeter. A means whereby, a
reversal of the direction of rotation of the dial is effected by the action of a

page_text: double-coil relay or other equivalent device at such times as the direction of the
current is opposite to the normal.
According to our invention we, primarily, have a registering plate suitably
graduated in terms of miles, which in one form of our instrument is turned by the
driven drum (one of two drums both suitably tapered) through a convenient
reduction of worm & gear wheels. The driving drum which is placed inversely
to the driven drum is worked by a clock preferably arranged within the drum
itself & may be graduated in hours & drives the second drum by an endless belt
or cord. The relative positions of this driving belt or cord on the drums is
regulated by the ampere measuring device to which it is attached for instance by
means of an endless belt led round a pulley on the armature, the attachment being
effected by a clutch preferably composed of four or more wheels, which enables
the first mentioned belt to revolve (round the drums) without allowing it to
alter its position from a given plane on the coned drums unless by the movement
of the armature. An alternative method of constructing our instrument is to
substitute in place of the two drums one pulley of a shape exactly proportional to
the curve which has been ascertained by experiment to illustrate the varying
capacity of a given type of battery at varying rates of discharge. This pulley
when revolved at constant velocity by means of clockwork will impart to a wheel
capable of being driven by it at any point on its surface axially, by friction or
otherwise, a rate of speed proportional to the capacity of the battery in the
same way that the curve is; this wheel is capable of travelling longitudinally on
a spindle or shaft whilst causing it to rotate by means of a sliding key, the said
spindle or shaft acting to drive the horizontal disc or indicating needle aforesaid
through a flexible joint. In this case the ammeter will govern the position of
the wheel by a belt or otherwise, along the drum axially, this wheel will be
pressed against the drum by a spring in order to insure sufficient friction between
the two to cause positive driving. Any convenient form of ammeter can be
employed capable of exerting the necessary amount of effort on the moving
parts. For instance an ammeter shewn at L, J, K, in Figs. IV & V the con-
struction of which will be evident from the drawing, or one such as shewn in
Figs. VI & VII where the velocity of a revolving armature is proportional to
the current in the circuit it is desired to measure, in this latter case the horizontal
belt of the two coned drums, or the sliding wheel in our alternative method, may
be varied in position by a centrifugal device driven by the revolving armature
the curve of the cones being suitably proportioned to the form of governor em-
ployed: In some cases we employ mechanism whereby at such times as the
current is above the maximum rate of discharge the armature of the ammeter
brings into action a suitable tape or other recording device and at the same
time causes a bell to ring or other indication to be given & continued so long as
this rate of discharge remains above the maximum permissable. The reversing
mechanism above referred to may preferably consist of a double-coil relay forming
a local circuit & actuated by a polarized armature which puts in circuit either one
or the other of the two relay coils in accordance with the direction of the current
in the main circuit; thus by means of suitable reversing mechanism the direction
of rotation of the drums and consequently the dial is reversed. The instrument
is equally suitable for registering the recharging of the battery. In sucli case how-
ever special provision is made for reducing the speed of the recording device "so
as to allow the percentage of charge over discharge requisite to charge the cells
fully. The mechanism for this purpose may consist of any convenient form of
reversing gear, so arranged that in one position viz. that which operates to record
charge, the indicating device will show a lower velocity than when working in
the opposite direction to record discharge.
:
トゥ
Referring to the drawings in which like letters refer to like parts, Figure I is a
side elevation. Fig. II an end elevation and Fig. III a plan, showing parts of
the same method of construction. Fig. IV is a side élevation of the first form of
instrument described. Fig. V'is á plan of Fig. IV. Figs. VI and VII show

page_text: diagrammatically an alternative form of current measuring device for controlling
the varying mechanism. Figs. VIII and IX are a plan and elevation showing
one method of arranging our automatic high discharge registering device.
Fig X is a plan and Fig XI an elevation of a sufficient portion of the reversing
mechanism to show diagrammatically, our invention. In Figs. I, II and III
A is the pulley the shape of which is proportional to the ascertained
capacity, curve, driven at constant velocity by the clock B through
the reversing device C, by means of a vertical spindle (not shewn), con-
nected thereto, D is a pulley kept always in contact with the coned drum A by
the spring E whilst free to slide axially along the spindle or shaft at the same
time capable of rotating the said shaft by means of a sliding key. G is a universal
joint enabling the shaft F to revolve at any angle necessitated by the position of
the wheel D. H is the tangent reduction gearing driving the needle I. J is
the electro-magnet of the ammeter device which when current circulates through
the coil K attracts the armature L which is free to revolve on its centre and in
compressing the spiral spring M takes up a position proportional to the strength
of the current flowing, at the same time by means of the belt or cord N running
over the pulleys O causing the position of the pulley D to be varied likewise,
whilst being prevented from moving laterally by the guides P. Q is a double
relay which when the main current flows in one direction through K causes
the arm R to actuate the reversing and compensating device C in one direction
or the other in accordance with the position of the polarized magnet S which
places in circuit either of the coils of the relay Q through one or other of the
platinum contact pieces S¹ and S².
In Figs. IV and V the coned pulleys A' and A2 take the place of A whilst the
belt and belt shifting device D2 take the place of D.
In Fig. VI, the armature L revolving within the magnets J imparts by its
velocity which is proportional to the current a centrifugal force to the balls Ja
acting by means of the lever Je to control either the belt shifting device D' D' or
the pulley wheel D.
In Figs. VIII and IX the armature L is arranged relatively to the stop or
spindle T, in such a way that at such times as the current flowing exceeds a
given amount, the spindle or stop T on the rocking lever U, pivotted at V. will
be deflected, causing the wheel W to gear with the moving wheel X revolving
with the drum A or A¹. The tape Y will then be fed from the drum Y' by
means of the wheel W₁ fixed to the same spindle as W between the milled
wheel W and the milled wheel Z causing the tape to be indented in passing
finally on to the winding-in drum Y which keeps the tape taut by means of a
wound spring (not shewn).
In Figs. and XI A3 and E are two bevel gear wheels of different diameters
fixed to the driving spindle J. B¹ and F are bevel gear wheels of different
diameters fixed to the driven spindle I¹ of the drum A. The spindle K¹ which
is capable of axial movement carries three hevel wheels C D and G¹, of
these C and D are fixed to the spindle K¹, but G which permanently gears
with F, being kept in position by suitable means, is free to turn on the spindle K¹
as long as the bevel wheel C is in gear with A3 and B¹, if however an axial move-
ment he given to the spindle K' which thereby draws C¹ out of gear with A³
and B the same movement, will simultaneously cause E¹ and D³ to engage
together, and by means of suitable clutch gearing, cause G¹ to revolve with and
be driven by the spindle K¹.
It will be understood that such proportionate diameters are given to the various
hevel wheels that when the train A³ C₁ B₁ is in gear. the speed of rotation of
the drum A will be less than when the train D E G F¹ is in gear, and also that
in the one case. the direction of motion of the drum A will be in a contrary
direction to that in the other case.
The position of the spindle K¹ is controlled by the forked reversing lever R¹
which is actuated in one direction or another by the armature Q¹.

page_text: It will be seen that when the cells are discharging and the current is in the
normal direction the armature Q¹ will take up a position within the solenoid Q
causing the forked reversing lever R¹ to move the spindle K¹ with the two bevel
wheels fixed thereon sufficiently to disengage C¹ from A3 and B', and, by means of
the interlocking of the clutch gear before mentioned to put into train the
wheels D³ EGF, thereby giving motion to the drum A in one direction.
Conversely when the direction of the current is reversed in charging, the
armature Q by taking up an opposite position, will cause the train of wheels D3
EGF to be disengaged, and the train A³ C and B' to engage thereby giving
less velocity and a contrary direction of rotation to the drum A, and to the
revolving needle I (shewn in Figs. 1 and III of Sheet I and in Fig. IV of
Sheet II) the amount of this reduction in velocity being proportional to the
degree of overcharge required by, and arranged to be given to, the battery.
It will be readily understood by those conversant with the art that in con-
structing the variable gear the form of the conical surfaces or equivalent device
must be so designed that at each position of the gear changing mechanism
corresponding to a certain rate of discharge the relative diameters of the inter-
gearing pulleys shall be exactly proportionate to the capacity of the battery at
that particular rate of discharge. The "capacity for rate" curve varies as it is
well known with different types of battery and can be ascertained by experiment.
In the figures accompanying this specification diagrammatic forms of con
struction are shewn.
We have shewn in our drawings two alternative forms of variable gear but it
is evident that other methods of arrangement might be evolved embodying the
chief points of importance which would form an element of our combination. It
will be easily understood that in connection with the compensating & reversing
gear described the charging current may be automatically cut off after a battery
is fully charged by means of, for instance, the circuit of an automatic cut-out
being closed by the recording needle through two platinum points. We are
aware that it has been proposed to construct ampere-hour meters of a combination
of a clock and an ampere measuring device in which the variations of the clock
are simply proportioned to the current flowing. The essential difference, to these
latter, in our invention above described, is that the variations in speed are pro-
portioned not only to the current flowing but also to the capacity for rate function.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
I. In an ampere-measuring device the combination, in an instrument for
recording the amount of charge remaining in or given to a secondary battery, of
clockwork or other equivalent device actuating a dial recording miles or kilowatt
hours, & mechanism for varying the speed of the recording device in a ratio pro-
portionate to the rate of discharge or charge as indicated by said ampere measur-
ing device and to the ascertained variation of capacity consequent, to such rate
for a given battery for the purposes described.
II. An integrating Coulomb meter comprising the combination of (I) an
ampere-measuring device; (II) a variable gear, whose variations are proportional
to the varying capacities of a battery at different rates of discharge and are
effected by the movements of the ampere-measuring device; (III) clockwork or
other mechanism giving uniform motion actuating a device recording miles or
kilowatt-hours through variable gear for the purposes described.
III. The integrating Coulomb meter comprising the combination of ampere
measuring device variable gear and clockwork mechanism substantially as &
for the purposes described.
IV. In an integrating Coulomb meter the automatic electrically operated revers-
ing and compensating gear for allowing the requisite increase of energy on
recharging, substantially as described.

page_text: V. The combination with an integrating Coulomb meter of a tell-tale and
recording device for abnormal discharges as & for the purposes described.
VI. In a Coulomb meter the use of variable gear comprising a conical integrat-
ing pulley or pulleys having curved surfaces as and for the purposes described.
T1 101 1.
T1000
PERCY W. NORTHEY.
THE ELECTRIC MOTIVE POWER COMPANY LIMITED.
PERCY W. NORTHEY,
Managing Director.