Improvements relating to Electric Current Meters.
Year: 1896

page_text: Date of Application, 8th May, 1896
Complete Specification Left, 8th Feb., 1897-Accepted, 1st May, 180
PROVISIONAL SPECIFICATION.
Improvements relating to Electric Current Meters.
1, REGINALD PAGE WILSON, of 68, Victoria Street, Westminster, in the
County of London, Consulting Engineer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to electric current meters, and has for its object to provide
a 'differential device by which current used at different periods or parts of a day
may be separately metered and automatically registered so that differential rates or
charges may be made for current consumed, for example, lower rates during the
day hours of minimum demand and higher rates during the evening and night
hours of maximum demand, and thus encouragement will be afforded to consumers.
to use the current supplied at those times when there is least duty on the
generating plant.
My invention comprises an automatic switch attachment for ordinary meters
whose function is to alter the number of ampere turns in the series coils or the
resistance in the shunt circuit of the meter as the case may be. In adapting same
I employ a metal disc mounted upon a shaft and rotated preferably by a self-
winding clock once in 24 hours or as required, suitable insulation being provided
where necessary. Upon the same shaft is mounted one or more shields or quadrants
covering or embracing a part of the periphery of the disc, and upon the disc is
mounted a cam preferably of volute or snail-wheel shape and so constructed as to
be able to cover wholly or in part the outer edge of the shield or quadrants. The
position of this cam in relation to the quadrant and also of all devices in relation
to the spindle is adjustable to suit circumstances by a clamp or equivalent device,
and they all move together. Two or more electric circuits may be used, each
connected to a spring contact device rubbing upon the periphery of the rotating
disc during its revolution except for such part or parts as is or are covered by said
shield or quadrants over which it is raised by the cam, and one circuit is thus
completed through the cam and di-c to the meter or meters. When the rubbing
contact passes off the volute cam it falls and rubs upon the outer edge of the shield
or quadrant then underlying same, and another circuit is then completed. In this
circuit however is placed a suitable resistance through which the current passes.
before entering the meter, thereby causing a less amount of current or energy to be
registered for that period of time occupied by the shield or quadrant passing under
the said contact device. Similarly when two meters are used the armature of one
may be thrown out of action by this automatic change of circuit.
An index hand and scale are arranged between the quadrant and disc to record
their relative positions, and arranged in such manner that the distance of travel of
the contact maker over the quadrant can be accurately ascertained by inspection
as and when required.
Thus the amount of current consumed during any given period of a day is
registered in proportion to the rate to be charged for same.
In combination with apparatus such as is above described it is advantageous to
use a device for indicating to the consumer the rate at which current is being
charged for at any time. To this end I employ solenoids corresponding in number
to the different rates charged, and each connected in series with its own circuit, and

page_text: adapted when energised to attract an armature and expose a disc on which is
marked the price per unit for the time being.
J. C. CHAPMAN,
Agent.
Improvements relating to Electric Current Meters.
I, REGINALD PAGE WILSON, of 68, Victoria Street, Westminster, in the
County of London, Consulting Engineer, do, hereby declare the nature of this
invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My invention relates to electric current meters, and has for its object to provide
a differential device by which current used at different periods or parts of a day
may be separately or proportionately metered and automatically registered so that
differential rates or charges per unit may be made for the current consumed, for
example, lower rates during the day hours of minimum demand, so that encourage-
ment may be afforded to consumers to use the current at times when there is least
duty on the generating plant.
My invention comprises an automatic switch attachment for ordinary meters
whose function is to alter the number of turns in the series coils or the resistance in
the shunt circuit of the meter as the case may be.
In fully describing my invention 1 will refer to the accompanying drawings in
which
Fig. 1 shows my switch in elevation and a diagram of connections by which
the resistance in the shunt circuit of the meter may be automatically altered to
effect my purpose.
Fig. 2 shows a diagram of connections in which two meters are used, or
alternatively one meter in which the ampere turns in the series coils are varied,
and
Fig. 3 is a transverse section on line 1-2 of the switch as it appears in
Fig. 2.
1 will assume that the differential rates to be charged are 3d. and 6d.
In carrying out my invention I employ a special construction of automatic time
switch consisting of a metal disc D of good conductivity which may with advantage
be provided with a silver contact edge in the usual way. It is mounted on a
shaft B and completely rotated preferably by a self-winding clock once in 24 hours
or as required, suitable insulation d' between shaft and disc being provided; upon
the same shaft B is mounted so as to be revoluble thereupon a shield or quadrant Q
covering or embracing a certain part of the periphery of the disc D. Upon the
disc D is formed or cut out or mounted a cam C preferably of the volute or snail
wheel shape such as is shown in Figs. 2 and 3 and so constructed as to be capable
of covering, according to its position, wholly or in part the outer edge of the
quadrant Q. The quadrant Q has a flat peripheral flange g adapted to pass freely
around within the space between the disc D and the cam C, suitable air gaps being
left at each side thereof as shown best in Fig. 3. The position of the quadrant Q
in relation to the cam C and of both of these devices in relation to the clock-
driven spindle B is adjustable to suit circumstances by a clamp device such as the
screwed spindle and nuts b', so that when the switch has once been adjusted and
clamped, the parts will all move together. The important advantage of this universal
adjustment is that the switch may be so set that the 6d. rate commences at any hour
of the day and continues for any required or determined period. An index hand q¹

page_text: is fixed to the quadrant Q and a graduated hour scale J is marked upon the dise D
whereby the distance of travel of the contact maker T over the quadrant Q
can be accurately ascertained by inspection when required. Referring to the
diagrammatic parts of Fig. 1. the coutact T is electrically connected by L' with
the armature A, 1 is the source of supply, X the distributing circuit, P and P
represent motors, lamps or other translating devices, E E' are the series coils and
E E the compounding coils of the meter. A its armatare and a the commutator.
It will be seen that 2 compounding coils E' E are shown in the figure, only one
of which is in use when the full current is flowing through it to the armature A,.
but when the meter is to register at half rate the compounding effect is increased
by utilising part of the added resistance to form an additional compounding coil..
Two or more electric circuits may be connected to the switch; for the sake of
clearness, two only are shown diagrammatically at L' L, ench is connected through
a spring contact device T2 T3 rubbing respectively upon a raised circular path d
on the disc D, and on part of the frame of the quadrant Q. A circuit will there-
fore be completed by the springs T T through the can and dise or by the
springs T and T through the quadrant. When by the rotation of the dise D
the rubbing contact T' passes off the cam C it falls and rubs upon the outer edge
of the quadrant Q as shown and one circuit is then broken and the other circuit
completed. In circuit with I and L are placed suitable resistances R R' through
which the shunt current of the meter passes, thereby causing a more or less amount
of current or energy to be registered for that period of time which is occupied by
the quadrant Q passing under the said contact device T'. Similarly when two
meters are used the armature of one may be thrown out of action by this automatic
change of circuit.
Thus the amount of current consumed during any given period of a day is
registered in proportion to the rate to be charged for same during that period. In
some cases it may be preferable in connection for example with ampere hour
meters to use two meters or to so arrange the winding of 1 ineter as to provide for
the alteration in the ampere turns in such proportions as may be required.
In such enses I so construct the relay whose primary object is to show the rate-
at which the current is being charged at any given moment that it shall operate an
ordinary switch suitable for altering the connections as above explained. Such an
arrangement is diagrammatically shown in Fig. 2, wherein M' M' are two ampere
hour meters so connected that one only is in use during the hours when the 3d. rate
is charged, while both are in use during the hours when the Gd. rate is charged, so
that M³ registers the total amount of anits supplied when M¹ only registers these
supplied at the 6d. rate. In cases where it is not considered necessary to have a
record of the actual number of units supplied at each rate, a meter with a duplicate
winding may be used as shown dotted at M³ Fig. 2. In this case the number of
ampere turns is so varied that the meter registers at double the speed during the-
6d. rate that it does during the 3d. rate.
In combination with apparatus such as is above described it is advantageous to.
use a device for indicating to the consumer the rate at which current is being
charged for at any time. To this end I employ an arrangement of solenoids S S
corresponding in number to the different rates charged, (which are assumed to be
6d. and 3d.) ench solenoid is connected in series with its own circuit, and adapted
when energised to attract an armature s and expose a disc or tablet on which is
marked the price per unit for the time being.
It will be seen that in both the two cases above described my improved time
switch serves to energize the solenoids S and S' which, in addition to indicating
the rate at which the current consumed is being charged for at any given moment,
also actuate in turn the switch lever H and thereby alter the connections of the
meter or meters so as to produce the result above described. Manifestly any
convenient form of switch with mercury or rubbing contacts may be used to alter
these connections, but the switch shown diagrammatically in Fig. 2 will serve to
illustrate the method. Further it may be advisable to so construct and arrange

page_text: the switch lever that the circuit of the solenoid which has attracted it becomes
broken when the lever H arrives at its ultimate position. The object of this is of
course to avoid loss of energy which would result from unnecessarily keeping one
solenoid always energized. It will generally be necessary to commence or terminate
the higher or 6d. rate at different hours of the day (varying with the period of the
year), and to facilitate this operation the connection between the clock and the
switch is made in such way that the moving by hand of the pointers of the clock
serves to adjust the switch as follows.
Assume for example that it is desired to commence the 6d. rate at 4 p.m., and
to terminate it at 7 p.m. first, set the hands to 4 o'clock, then loosen the clamps bb
and adjust the disc D on the spindle B so that the contact T' just falls off the end
of cam C. Then again move the hands until the clock stands at 7 o'clock, then
adjust the quadrant until the spring T just falls off its end, then clamp all together
by tightening up and start the clock, having previously set it to the proper
(or "Greenwich") time. The automatic switch attachment is then ready when
4 o'clock arrives to alter the meter connections so that 6d. will be charged for
the units consumed until 7 o'clock when the contact T' will fall off the cam C and
return to the disc thereby completing circuit L L and indicating the 3d. rate of
charge.
I prefer to use a clock equipped with an ordinary arrangement of day dials and
gear fitted with a clutch so that they may be set to zero, for indicating by
inspection how long the clock has gone since it was last wound up, and consequently
what length of time has elapsed since it stopped.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. For separately or proportionately metering and automatically registering the
amount of electric current used at different periods or parts of a day, the use and
combination with an electricity meter of the clock-driven automatic switch
attachment capable of universal adjustment to suit any periods of time and
constructed and adapted to operate as above described.
2. The construction of the automatic clock-driven switch attachment above
referred to, comprising the rotary metallic clock-driven disc D, the revoluble shield
or quadrant Qwith flat peripheral flange g, the snail-wheel cam C, the means for
universal adjustment of the parts, the rubbing contacts T1 T2 T3 and iudicating
devices, all arranged and adapted for use substantially in the manner and for the
purposes herein set forth.
3. The use in electricity meters of the improved arrangement for automatically
controlling the ratio which the amount of electrical energy or current consumed
bears to the current registered, consisting essentially of the elements herein
specified, all constructed, connected, and operating at the times and substantially
in the manners herein described and illustrated in the drawings.
Dated this 8th day of February 1897.