IMPROVE- MENTS IN ELECTRICAL METERS
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford of 42 Southampton Buildings
in the County of Middlesex, Patent Agent for an Invention of "IMPROVE-
MENTS IN ELECTRICAL METERS". Communicated to him from abroad by
Thomas Alva Edison of Menlo Park in the State of New Jersey United
States of America.
PROVISIONAL SPECIFICATION left by the said Thomas John Handford
at the Office of the Commissioners of Patents on the 10th July 1882.
"
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN ELECTRICAL METERS a communi-
cation to me from abroad by Thomas Alva Edison of Menlo Park, in the State of
New Jersey United States of America
The object of this Invention is to produce an automatically registering meter,
for measuring the electrical energy consumed in a circuit, which shall be simple in
construction and efficient in operation
'
This is accomplished by the use of two electrolytic cells, two of the electrodes
(one of each cell) being suspended from the ends of a beam which is supported or
suspended so as to oscillate or turn upon its centre. These cells are arranged in a
shunt circuit around resistance placed in the line of one of the main conductors of
a house circuit and have connected with them a circuit making and breaking
device, operated by the beam by which the current of the shunt always passes
through the cell having its electrode elevated or depressed, according to whether the
meter is acting by depositing upon or stripping from the suspended electrodes. The .
deposit upon the elevated electrode increases its weight until it overbalances the
depressed electrode at the other end of the. beam and the beam is tipped; or
metal is stripped from the depressed electrode until it becomes lighter than the
elevated electrode, when the same movement takes place. This movement is
utilized to break the circuit of the cell through which the current has been passing
and to complete the circuit of the other cell. The movement of the beam is also
used to work a registering apparatus either by making and breaking the circuits

page_text: of electro-magnets, or by a mechanical connection with the beam or a part moved
by it. The electro magnets (if used) may be in circuit with the cells, or in other
circuits. For example they may be in a multiple arc circuit from the main con-
ductors of the house circuit with additional resistance if required. In that case
the circuit controller operates an additional pair of arms which are insulated from
the rest of the circuit controller
In order to register a partial movement of the beam, a scale may be provided
The beam
upon which travels a finger attached to or worked by the beam.
continues to tip back and forth and its movements are indicated by the register,
the suspended electrodes acting as the cathodes of the cells and receiving additional
weight, alternately, or acting as the anodes and being stripped alternately. At the
end of each month, or other fixed period, the direction of the current through the
cells and the connections of the circuit controller are reversed, and the suspended
electrodes become the anodes of the cells if they have been acting as the cathodes,
during the previous month, or the cathodes if they have before acted as anodes.
In order to effect the reversal of the current and the connections of the circuit
controller, a simple hand reverser is used for each purpose, the two being by
preference mounted upon a common spindle, and worked simultaneously by the
employé of the lighting company who makes note of the condition of the meter.
In order to maintain electrical connection with the working beam, such beam is
provided with a rod at one end dipping in a cup of mercury, which keeps the
parts in good electrical contact without producing friction. The circuit controller
worked by the beam makes and breaks the circuits of the cells by means of
mercury cups and points, which are dipped into and raised out of the mercury, the
movement thus requiring very little power. The working beam has its movement
retarded by means of a reciprocating dash-pot, so as to assure regularity, and
prevent the meter from being affected by jars. A compensating resistance is
placed in the circuit of the cells so as to compensate for changes in resistance
caused by variations in temperature; and a lamp or other heating resistance the
circuit of which is closed by a thermostatic device, is used with each meter, to
prevent the freezing of the solution of the cells. In connection with each automatic
meter, a simple electrolytic cell meter may be used, to keep the record intact if the
automatic meter should become inoperative. For this extra cell, as well as the
cells of the automatic meter, there are preferably used amalgamated zinc electrodes.
placed in a solution of sulphate of zinc

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas John Handford in the Great Seal Patent Office on the
9th January 1883.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS IN ELECTRICAL METERS " a communi-
cation to me from abroad by Thomas Alva Edison of Menlo Park in the State of
New Jersey United States of America
The said Invention has for its object producing an automatically registering
meter for measuring the electrical energy consumed in a circuit which shall be
simple in construction and efficient in operation..
This is accomplished by the use of two electrolytic cells two of the electrodes
(one of each cell) being suspended from the ends of a beam which is supported or
suspended so as to oscillate or turn upon its centre. These cells are arranged in a
shunt circuit around resistance placed in the line of one of the main conductors of
a house circuit and have connected with them a circuit making and breaking
device operated by the beam by which the current of the shunt always passos
through the cell having its electrodes elevated or depressed according to whether
the meter is acting by depositing upon or stripping from the suspended electrodes.
The deposit upon the elevated electrode increases its weight until it overbalances
the depressed electrode at the other end of the beam and the beam is tipped or
metal is stripped from the depressed electrode until it becomes lighter than the
elevated electrode when the same movement takes place. This movement is
utilized to break the circuit of the cell through which the current has been passing
and to complete the circuit of the other cell. The movement of the beam is also
used to work a registering apparatus either by making and breaking the circuits
of electro magnets or by a mechanical connection with the beam or a part moved
by it. The electro magnets (if used) may be in circuit with the cells or in other
circuits. In order to register a partial movement of the beam a scale may be
provided upon which travels a finger attached to or worked by the beam. The
beam continues to tip back and forth and its movements are indicated by the
register the suspended electrodes acting as the cathodes of the cells and receiving
additional weight alternately or acting as the anodes and being stripped alternately.
At the end of each month or other fixed period the direction of the current through
the cells and the connections of the circuit controller are reversed and the suspended
electrodes become the anodes of the cells if they have been acting as the cathodes
during the previous month, or the cathodes if they have before acted as anodes. In
order to effect the reversal of the current and the connections of the circuit
controller a simple hand reverser is used for each purpose the two being by
preference mounted upon a common spindle and worked simultaneously by the
employé of the lighting company who makes note of the condition of the meter.
In order to maintain electrical connection with the working beam such beam is
provided with a rod at one end dipping in a cup of mercury which keeps the parts
in good electrical contact without producing friction. The circuit controller worked
by the beam makes and breaks the circuits of the cells by means of mercury cups
and points which are dipped into and raised out of the mercury, the movement
thus requiring very little power. The working beam has its movement retarded by
means of a reciprocating dash-pot plunger so as to assure regularity and prevent
the meter from being affected by jars. A compensating resistance is placed in the
circuit of the cells so as to compensate for changes in resistance caused by variations

page_text: in temperature and a lamp or other heating resistance the circuit of which is closed
by a thermostatic device is used with each meter, to prevent the freezing of the
solution of the cells. In connection with each automatic meter a simple electrolytic
cell meter may be used to keep the record intact if the automatic meter should
become inoperative. For this extra cell, as well as the cells of the automatic meter
there are preferably used amalgamated zinc electrodes placed in a solution of
sulphate of zinc.
And in order that the said Invention may be perfectly understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the accompanying sheet of drawings the same letters of
reference indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawings is an elevation partly diagrammatic
of the meter; Figure 2 a perspective view partly diagrammatic with modified
connections for the registering electro magnets and Figure 3 a view of detached
parts showing means for operating the register mechanically from the working
beam,
A and B are two electrolytic cells each composed preferably of two cylindrical
electrodes of amalgamated zinc placed in a solution of sulphate of zinc as described
in the Specification to Letters Patent granted to Edward Griffith Brewer dated
19th October 1881 N° 4576. One electrode of each cell is suspended from the
end of a beam C which is pivoted or suspended to turn centrally. At one end
this beam is connected with the reciprocating plunger of a dash pot a, while at its
other end it has a rod projecting into a mercury cup 6 and kept constantly
immersed in the mercury of the cup.
The beam C has an arm or finger c projecting therefrom which plays in the
U shaped yoke d of a pivoted circuit controller D the parts being insulated to
prevent short circuiting the cells. This circuit controller has three arms; a
vertical arm which has the yoke d at its end and two horizontal arms e e¹,
provided with points dipping in mercury cups ff. The circuit controller is
pivoted at the junction of the three arms and its vertical arm has an adjustable
weight g, to throw the circuit controller when it is carried over the centre by the
arm c of the beam C. E E¹ are two electro-magnets acting upon an intermediate
armature lever h the movement of which works the register F. G G are simple
hand operated current reversers which are shown separated for clearness of
illustration but which in practice are mounted on a common spindle and moved
simultaneously. 1.2 are the main conductors of a house circuit having placed
therein a resistance R, around which is the shunt circuit through the meter.
This shunt has wires 3, 4, running from opposite sides of the resistance to the
current reverser G; from one spring of the current reverser a wire 5 extends to
the circuit controller D; from the other spring of the current reverser a wire 6
extends to the mercury cup b; and from the stationary electrodes of the cells A B
wires 7, 8 extend to the coils of the electro-magnets E E¹ (Figure 1), and thence
to the current reverser G³ and the mercury cups ƒfƒ¹. A resistance R' is placed
in the shunt circuit at any particular point common to both cells to compensate
for variations in the resistance of the cell in circuit caused by changes in the
temperature of the solution.
The apparatus operates in the following manner reference being had more
especially to Figure 1; Assuming the reversers to be in the position shown in
Figure 1 and the beam C depressed at cell A and elevated at B then the arm e'
of the circuit controller D will be depressed making contact with the mercury in
cup while arm e will be elevated breaking contact with mercury in ƒ as shewn.
The current in the shunt will then be from 2 on one side of R by wire 4,
through G by. wire 5 through D cup f¹ reverser G' electro-magnet E¹ wire 8
from stationary to suspended electrode of cell B, beam C cup b wire 6 resistance R¹
reverser G and wire 3 to 2 on the other side of the resistance R.
E' will attract h as shewn causing it to work the register with one impulse and
there will be a deposit upon the elevated suspended electrode of B until its weight

page_text: overcomes the weight of the depressed suspended electrode of A when the beam C
will be tipped the movement being regulated by dash-pot a and the electrical
connection with C being maintained by the mercury cup b. Now the point of e
will be in the mercury of cup f while the point of e' will be raised out of the
mercury of cup f'. The current will now flow from 2 by 4 G, 5, D ƒ, G¹,
electro-magnet:E, 7, from stationary to suspended electrode of cell A, C, b, 6, R¹ G,
3 back to 2.
The Electro-magnet E will now attract h giving another movement to, the
register while the deposit will be upon the. elevated suspended electrode of A
which will finally overbalance the depressed suspended electrode of B causing the
beam C to tip again and repeating the operation. In this operation the suspended
electrodes act as the cathodes of the cells and the meter works by depositing metal
first upon one electrode and then upon the other.
At the end of a month or after any other lapse of time the reversers G G¹
will be turned. The stationary electrodes will then become the cathodes of the
cells and metal will be stripped from each suspended electrode when in a depressed
position until it becomes lighter than the elevated electrode when the beam will
be tipped. The course of the current in that case will be explained in connection
with figure 2 which shows the reversers shifted.
In this figure there is especially shewn a modification of the connections of the
electro-magnets E E which operate the register. Instead of having those electro-
magnets directly in the circuit of the meter they are in a multiple arc circuit 9, 10
from 1, 2 with additional resistance R³ if required. In this case the circuit con-
troller D operates an additional pair of arms i i¹ which are insulated from the
rest of the circuit controller and carry points dipping in mercury cups k k¹. The
wire 9 runs to the arms i i¹ and from the mercury cups k ke the circuit divides to
the two electro-magnets E E¹ from which the wire 10 extends to the other main
conductor. With this construction the wires 7. 8 pass from the stationary
electrodes of the cells directly to the current reverser G₁ and do not connect with
the coils of the electro magnets E E. Each time the circuit controller D is moved
by the movement of the beam C the circuit of one of the electro magnets E E¹ is
broken and that of the other electro magnet completed thus working the register.
When the reversers are shifted to inake the suspended electrodes the anodes of tho
cells (figure 2) the current will take the following course :-Assuming the beam C
to be depressed at cell A and the point carried by arm e¹ to be immersed in the
mercury of cup f¹ as indicated in the drawing the current passes from 2 on one
side of R by wire 4 to G thence by wire 6 resistance R' to cup b then by beam C
to the moveable electrode of cell A and from there to the stationary electrode of A
and by wire 7 to reverser GT cup f' controller D wire 5 reverser G and wire 3
back to wire 2 on the other side of R. Metal will be stripped from the suspended
electrode of A when it will be overbalanced by the elevated suspended electrode
of B causing the beam C to tip and the arm e to make contact in f. Now the
current will be from 2 on one side of R via 4, G, 6, R¹ b, C through cell B from
the suspended to the stationary electrode, 8, G³, ƒ, D, 5, G, 3 to 2 on the other
side of R.
•
"
The suspended electrode of B will now be stripped until lighter than that of A.
when the beam C will again be tipped and the operation repeated. The electro
magnets E E' work the register at each movement of C as before explained. The
register is worked by complete movements of the beam but is not affected by a
partial movement which it may be desirable to take account of. For this purpose
a scale S Figure 1 is placed at the back of the arm or finger c or is otherwise
arranged in connection with the beam C. so that it will show partial movements
of such beam.
In lieu of using electro-magnets to operate the register an arrangement operated
mechanically by the movement of the beam C may be employed. A construction
for the purpose is shown in Figure 3 wherein an arm H projects downwardly from
the pivoted circuit-controller D and by its movement works the register. An

page_text: incandescing electric lamp or other form of heating resistance the circuit of which
is closed by a thermostatic device is used in connection with the meter to prevent
the solution of the cells from freezing as described in the former specification
before referred to. In connection with each automatic meter there is preferably
used a simple electrolytic meter I placed with compensating resistance in a
shunt circuit 11, 12 around a resistance in one of the main conductors of the
house circuit. This extra cell furnishes an accurate and reliable means of calculating
the consumption and it's plates may be weighed if the automatic meter gets out of
order or as a check upon its accuracy.
•
T
I
The automatic meter hereinbefore described differs essentially from that set forth
in the Specification to Letters Patent granted to Peter Jensen dated' the
27th October 1880 N° 4391 in which the movement is produced by taking metal
from one and adding metal to the other of two counterbalancing electrodes simul-
taneously the current being reversed at each movement, whilst in the meter
hereinbefore described as forming the subject of the present Invention the move-
ment is produced by first adding metal to one and then adding it to the other of
two counterbalancing electrodes or first taking metal from one and then from the
other of two counterbalancing electrodes the current being reversed periodically by
hand reversers. The counterbalancing electrodes are thus both of the same nature
being both cathodes or anodes and never one an anode and the other a cathode.
The use of a complicated automatic current-reverser is thereby avoided and the
meter made more simple and efficient and less liable to get out of order.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is:-
First An electrical meter operating by adding metal to counterbalancing
cathodes alternately without taking from either electrode, or by stripping metal
from counterbalancing anodes alternately without adding to either electrode, a
registering mechanism being operated indirectly or directly by the movements
produced thereby substantially as herein before described.
Second-In an automatically registering electrical meter the combination of two
electro-depositing cells, a centrally supported or suspended beam from which one
electrode of each cell is suspended, means for completing the circuit through the
cells alternately, and reversers for periodically changing the relation of the
electrodes of the cells, the several parts being arranged and combined together so
as to operate substantially as hereinbefore described.
Third: An automatically registering electrical meter having the movement of its
working mechanism retarded by a reciprocating dash pot plunger sübstantially as
hereinbefore described
. In witness whereof I the said Thomas John Handford have to this my
Specification set my hand and seal this ninth day of January One thousand