IMPROVEMENTS IN APPARATUS FOR MEASURING ELECTRIC CURRENTS
Year: 1884

page_text: I, JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London Fellow
of the Institute of Patent Agents do hereby declare the nature of my invention
for IMPROVEMENTS IN APPARATUS FOR MEASURING ELECTRIC CURRENTS to be as
follows:-
If water be allowed to flow through a given orifice under a constant pressure the
quantity of water which flows will be in proportion to the duration of the flow.
Again, if an orifice be fitted with a valve or closing device and this valve or device
be actuated by an electro magnet so as to be raised or opened when the current
passes through the coils of the electro magnet and so as to return immediately to
its closed position when the electric current ceases to pass, the quantity of water
which has flowed through the orifice will be in proportion to the time during which
the electric current has passed through the coils of the electro magnet.
Now suppose a valve or closing device to be constructed so that the section of
the orifice giving passage to the water is constantly in proportion to the height to
which the valve is raised the quantity of water which flows through the valve will
be in proportion to the height to which the valve is raised. Consequently if this
height be itself in proportion to the intensity of the current which magnetizes the
cores of the coils the quantity of water which flows through the valve will be in
proportion to the intensity of the current and can be made to measure the quantity
of electricity which bas traversed the circuit during a given time. The apparatus
which forms the subject of the present invention is based upon this principle.
For the purpose of explaining the invention I will suppose there are three
electric lamps with three distinct derivations from the main electric circuit, but
there may be any other desired number of luminous centres the number of valves
being made to correspond. The current from one of the poles of the generator
goes to a distributing commutator fixed to the meter or counting apparatus and
having as many contacts as there are coils or electro magnets-say three as above
stated. Each of the contacts communicates with the corresponding coil.
traversing the wire of these electro magnets the current magnetizes a rod (of
nickelized iron) fixed to the valve corresponding to the electro magnet connected
Price B71
In

page_text: therewith and raises it in proportion to the intensity of the current. From the
coil the wire goes to the corresponding lamp and thence the current is led to the
return wire which is common to all the lamps. The return wire before reaching
the binding screw of the generator passes through a rod connected with a float and
this rod is in contact by friction with one end of a bar; this bar at its other end is
in contact by friction with another rod in connection with another float. It is from
these three pieces which are electrically insulated from the rest of the apparatus
that the current returns to the generator. The first named float is in a reservoir
from which water leaves the apparatus and the second named float is in a reservoir
by which the water enters the apparatus. The contact of the rods with the bar
exists only as long as the two floats are simultaneously in their normal position;
therefore the displacement of the one or the other from this position breaks the
circuit. Hence if the water level becomes lowered in the inlet reservoir the float
therein falls and the current is interrupted, and if the water level rises in the
outlet reservoir the float therein rises and the current is likewise interrupted.
The water enters the box which contains the various parts of the meter by a tube
which conducts it to the inlet reservoir. This tube has a cock which is opened
and closed automatically under the action of the float, and the lower end of the
tube is some distance below the water level in the reservoir so that the slow
introduction of the water causes no sensible fluctuation of the level. This level
which is in line with the centre of the float causes a slight depth or sheet of water
to cover a horizontal metal plate in which are formed the three outlet orifices fitted
with valves the action of which has been already explained. When under the
action of the electro magnet which corresponds to it one valve is raised the water
passing through the opened orifice flows in proportion to the extent to which the
valve is raised and enters a chamber below. The lower part of this chamber is
inclined and has an opening through which the water escapes. The water falls on
to a water wheel which it puts in motion and on leaving the wheel the water
enters the outlet reservoir before described and thence leaves the apparatus. The
water wheel is connected with the counting or integrating mechanism.
The apparatus may be modified in various ways:-for example a wheel of the
form used in turbines may be used instead of the water wheel; the valves may be
so arranged that in rising they establish a communication which gives rise to a
derivation in the circuit and prevents the lamp burning under a flow of the electric
current; and the coils may be arranged in derivation instead of being actuated by
a direct current as described.

page_text: Improvements in Apparatus for Measuring Electric Currents.
I JOHN CLAYTON MEWBURN, of 169 Fleet Street, in the City of London, Fellow
of the Institute of Patent Agents do hereby declare the nature of my invention
for "IMPROVEMENTS IN APPARATUS FOR MEASURING ELECTRIC CURRENTS" and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
If water be allowed to flow through a given orifice under a constant pressure
the quantity of the water which flows will be in proportion to the duration of the
flow. Again, if an orifice be fitted with a valve or closing device and this valve or
device be actuated by an electro magnet so as to be raised or opened when the
current passes through the coils of the electro magnet and so as to return
immediately to its closed position when the electric current ceases to pass, the
quantity of water which has flowed through the orifice will be in proportion to the
time during which the electric current has passed through the coils of the electro
magnet.
Now suppose a valve or closing device to be constructed so that the section of
the orifice giving passage to the water is constantly in proportion to the height to
which the valve is raised the quantity of water which flows through the valve will
be in proportion to the height to which the valve is raised. Consequently if this
height be itself in proportion to the intensity of the current which magnetizes the
cores of the coils the quantity of water which flows through the valvo will be. in
proportion to the intensity of the current and can be made to measure the quantity”
of electricity which has traversed the circuit during a given time. The apparatus
which forms the subject of the present invention is based upon this principle.
For the purpose of explaining the invention I will suppose there are 3 electric
lamps with 3 distinct derivations from the main electric circuit, but there may be
any other desired number of luminous centres the number of valves being made to
correspond.
The electric part of the apparatus is arranged as follows:-The current from one
of the poles of the generator goes to a distributing commutator (see Figure 1) fixed
to the meter or counting apparatus and having as many contacts as there are
coils or electro magnets-say three as above stated. Each of the contacts communi-
cates with the corresponding coil B B' or Bª Figure 3 and Figure 4; Figure 2
shows one of these parts in detail on a larger scale. In traversing the wire of these
electro magnets the current magnetizes a rod (of nickelized iron) fixed to the valve
corresponding to the electro magnet connected therewith and raises it in proportion
to the intensity of the current. From the coil the wire goes to the corresponding
lamp and thence the current is led to the return wire which is common to all the
lamps (see Figure 6). The return wire before reaching the binding screw of the
generator passes through a rod O P connected with a float F1 (Figure 3) and this
rod is in contact by friction with one end of a bar M N; this bar at its other end
is in contact by friction with another rod O¹ P' in connection with another float F.
It is from these three pieces which are electrically insulated from the rest of the
apparatus that the current returns to the generator. The float F¹is in a reservoir R¹

page_text: from which water leaves the apparatus and the float F is in a reservoir R by which
the water enters the apparatus. The contact of the rods O P and O' P¹ with the
bar M N exists only as long as the two floats are simultaneously in their norinal
position; therefore the displacement of the one or the other from this position
breaks the circuit. Hence if the water level becomes lowered in the inlet reservoir R
the float F therein falls and the current is interrupted, and if the water level rises
in the outlet reservoir R¹ the float F¹ therein rises and the current is likewise
interrupted.
The hydraulic part of the apparatus is arranged as follows:-The water enters
the box which contains the various parts of the meter by a tube C which conducts
it to the inlet reservoir R. This tube C has a cock at O¹ which is opened and closed
automatically under the action of the float F, and the lower end of the tube C is
some distance below the water level in the reservoir R so that the slow introduction
of the water causes no sensible fluctuation of the level, This level which is in line
with the centre of the float F causes a slight depth or sheet of water to cover the
horizontal metal plate in which are formed the three outlet orifices fitted with
valves (see Figure 2 for the details) the action of which has been already explained.
When under the action of the electro magnet which corresponds to it any one valve
is raised the water passing through the opened orifice flows in proportion to the
extent to which the valve is raised and enters a chamber V W X Y below. The
lower part of this chamber is inclined and has an opening at T through which the
water escapes. The water falls on to a water wheel H which it puts in motion
and on leaving the wheel the water enters the outlet reservoir R¹ and thence leaves
the apparatus. The water wheel is connected with the counting or integrating
mechanism.
The apparatus may be modified in various ways; for example a wheel of the
form used in turbines may be used instead of the water wheel; the valves may be
so arranged that in rising they establish a communication which gives rise to a
derivation in the circuit and prevents the lamp burning under a flow of the electric
current ;
and the coils may be arranged in derivation instead of being actuated by
a direct current as described.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed as communicated to
me, I declare that what I claim is
The apparatus constructed and acting substantially as hereinbefore described for
measuring electric currents.
Data LL 1
1002