IMPROVEMENTS IN APPARATUS FOR MEASURING ELECTRIC CURRENTS
Year: 1883

page_text: LETTERS PATENT to St George Lane Fox of Queen Anne's Gate in the
City of Westminster for an Invention of IMPROVEMENTS IN APPARATUS FOR
MEASURING ELECTRIC CURRENTS
PROVISIONAL SPECIFICATION left by the said St George Lane Fox at
the Office of the Commissioners of Patents on the 4th January 1883.
ST GEORGE LANE Fox of Queen Anne's Gate in the City of Westminster
"IMPROVEMENTS IN APPARATUS FOR MEASURING ELECTRIC CURRENTS
"
My Invention relates to apparatus for measuring electric currents on the principle
of the invention described in the Specification of former Letters Patent granted
to me and dated 14th November 1878 N° 4626 that is to say in such manner that
a counting or integrating apparatus which may be of any suitable kind is worked
and controlled by the movement and position (according to the strength of the
current) of the core of a solenoid or the armature of an electro magnet the core of
which solenoid or electro magnet forms part of the circuit or a shunted portion
of the circuit of the conductor the current passing through which is to be
measured.
My present improvements consist in combining with a solenoid or electro
magnet arranged as aforesaid and with the counting or integrating apparatus to be
worked or controlled thereby an arrangement by which the movement or position
of the solenoid core or armature is made to control the flow of water or other
fluid through a given passage the fluid which flows through this passage being
indicated by a gauge and the counting apparatus.
=
One manner in which the invention may be carried into effect is as follows:-
I attach the movable core of the solenoid (or the armature of the electro magnet)
to one end of a lever whose other end is connected to a conical valve or plug; this
valve controls the flow of water through an outlet or passage in the bottom of a
vessel which is kept charged at a constant level. The water which flows through the
outlet is received in a tank on the outside of which is a glass gauge for indicating
the level of water therein. Within the tank is a float which when the water has risen

page_text: to a given level at which there is an overflow moves a counter or integrator the
distance of one tooth. Then a syphon comes automatically into action so as to
empty the tank which will then be again gradually filled by the water from the
vessel above described.
When no current is passing through the coil of the solenoid the core is in its
highest position and the outlet above mentioned is completely closed by the valve;
when on the other hand a current is passing, the core is more or less drawn down
according to the strength of the current and therefore the valve is more or less
raised by the lever and the flow of water into the tank more or less great. By
making each tooth of tho counter indicate a given number of units of quantity
this counter combined with the quantity of water in the tank as shown by the
gauge will enable the amount of electricity which has passed through the solenoid
up to any given time to be at once ascertained.
In establishments where a comparatively small amount of electricity would be
required the arrangement for emptying the tank by means of the syphon can be
dispensed with because the tank would not become full between the periodical
visits of the inspector who would empty it after reading the gauge. In places
where water would be liable to freeze some other suitable fluid such as diluto
glycerine should be used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said St George Lane Fox in the Great Seal Patent Office on the
30th June 1883.
ST GEORGE LANE Fox of Queen Anne's Gate in the City of Westminster
"IMPROVEMENTS IN APPARATUS FOR MEASURING ELECTRIC CURRENTS
"
My invention relates to apparatus for measuring electric currents on the principle
of the invention described in the specification of former Letters Patent granted to
me and dated 14th November 1878 N° 4626, that is to say, in such manner that a
counting or integrating apparatus which may be of any suitable kind is worked
and controlled by the movement and position (according to the strength of the
current) of the core of a solenoid or the armature of an electro magnet the coil of
which solenoid or electro magnet forms part of the circuit or a shunted portion
of the circuit of the conductor the current passing through which is to be
measured.
My present improvements consist in combining with a solenoid or electro magnet
arranged as aforesaid and with the counting or integrating apparatus to be worked
or controlled thereby an arrangement as heroinafter described by which the
movement or position of the solenoid core or armature is made to control the flow
of water or other fluid through a given passage and the fluid which flows through
this passage is indicated by a gauge and the counting apparatus.
In the annexed drawings Figure 1 is a front elevation, Figure 2 a vertical
section, Figure 3 a side elevation and Figure 4 a plan of an apparatus constructed
according to my present invention for measuring electric currents. A is a solenoid
the coil of which forms part of the circuit or a shunted portion of the circuit of
the conductor the current passing through which is to be measured. B is the
movable core of this solenoid (or instead of the solenoid A and its core B I may
employ an electro magnet and armature as will be well understood). I attach the
core B of the solenoid (or the armature of the electro magnet) to one end of a
lever C which is pivoted at D and whose other end is connected to a valve or
plug E; this valve controls the flow of water through an outlet or passage F in
the bottom of the vessel G which is kept charged at a constant level from a
cistern H. The water which flows through the outlet F is received in a tank I on
the outside of which is a glass gauge K for indicating the level of water therein.
Within the tank is a float L which when the water has risen to a given level at
which there is an overflow moves a counter or integrator M the distance of one
tooth. Then a syphon N comes automatically into action so as to empty the tank I
which will then be again gradually filled by the water from the vessel G. 00 are
springs for adjusting the lever C.
The action is as follows:-When no current is passing through the coil of the
solenoid the core B is in its highest position and the outlet F is completely closed
by the valve E; when on the other hand a current is passing, the core B is more
or less drawn down according to the strength of the current and therefore the
valve E is more or less raised by the lever C and the flow of water into the tank I
more or less great. By making each tooth of the counter M indicate a given
number of units of quantity this counter combined with the quantity of water in
the tank I as shown by the gauge K will enable the amount of electricity which
bas passed through the solenoid up to any given time to be at once ascertained.
Figure 5 is a vertical section of a modified form of the apparatus in which the
valve or plug E instead of being connected to the lever C so as to move therewith
is fitted with a spring a just sufficient to raise the valve as that end of the lever is

page_text: raised by the bar B of the solenoid. b is a roller on the top of the valve rod for
the lever C to bear upon.
In establishments where a comparatively small amount of electricity would be
required the arrangement for emptying the tank by means of the syphon can be
dispensed with because the tank would not become full between the periodical
visits of the inspector who would empty it after reading the gauge.
Figures 6 and 7 represent another modification of my apparatus in which the
tank I is divided vertically into two compartments which become filled alternately
with the water which flows through the valve E. As soon as one compartment is full
the tank by a self acting arrangement' oscillates on a horizontal axis so as to bring
the other compartment into position below the valve E while the full compartment
is emptied by the opening of a valve. I' is the compartment or half of the tank
into which in the position shown the water flows from the valve E. As the water
rises in this compartment it lifts the float L which acting by the lever N' raises
and frees the retaining spring O'. The weight of the water in the compartment I¹
is thus allowed to move the tank over till it is caught by the spring P. As the
tank falls over, the valve Q is opened so that the water in I' escapes.
As soon as the weight of water in I' brings the tank over, the water from the
valve E flows into the other compartment 1' and rising in the same lifts the
float L' which actuating the lever I raises the spring P and so allows the tank to
fall back to its former position. These oscillations of the tank are caused to act
directly on the counter by the rod U.
In places where water would be liable to freeze some other suitable fluid such
as dilute glycerine should be used.
Having now described the nature of my said invention and in what manner the
same is to be performed I declare that I claim :-
Constructing apparatus for measuring electric currents substantially as here-
inhefore described and represented in the annexed drawings.
In witness whereof I the said St George Lane Fox have hereunto set my
hand and seal this twenty sixth day of June One thousand eight hundred
and eighty three.