Improvements in Self-recording Electric Meters.
Year: 1895

page_text: Date of Application, 15th Mar., 1895
Complete Specification Left, 15th Jan., 1896-Accepted, 14th Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in Self-recording Electric Meters.
I, ARTHUR WRIGHT of 26 Park Crescent Brighton Electrical Engineer do
hereby declare the nature of this invention to be as follows:-
The application of maximum or minimum recording liquid indexes, which record
by the displacement of liquid, to ampère & volt meters which work by electro
magnetism also the application of said recording liquid indexes to ampère & volt.
meters which work by the expansion of solids or liquids caused by the heat
generated by electric currents passing through or near them. The displacement-
of liquid constituting the index may be made in a variety of ways some examples
of which are shown in my Patent 583 of 1893, and said displacement may be
measured in any convenient way against a scale suitably divided.
Dated this 14th day of March 1895.
ARTHUR WRIGHT.
I, ARTHUR WRIGHT, of 26 Park Crescent, Brighton, Electrical 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:—
In the Complete Specification accompanying my Letters Patent No. 583 dated
the 11th day of January 1893 I describe what I, for the purposes of this
Specification, term "liquid indexes" in which the liquid constituting the index is
caused to overflow from one vessel or part of a vessel into another, the reading
being obtained either by measuring, as for example by a scale, the amount of.
liquid which has overflowed or the deficiency of liquid remaining in the vessel. In
the said Specification, which I may for convenience term my prior Specification,
the indication is produced by the expansion of air or gas heated by the electric
current passing through a resistance, the said resistance being in or near the body
of the air or gas to be expanded and the said expansion of air or gas causing the
movement of the body of liquid constituting the index.
My present invention relates to self-recording electric meters in which I obtain
the same results as in my said prior invention but by different means.
In my
present invention I obtain the necessary record by applying liquid indexes as
aforesaid to ampere and volt meters which work by (a) electro-magnetism, (b) the
expansion of solids, (c) the expansion of liquids.
(a.) In this type of my invention I apply to an electro-magnetic ampere or volt
meter a imaximum and or minimum recording liquid index. I may form a recording
instrument in accordance with my invention by adapting to an ordinary electro-
magnetic ammeter or voltmeter a vessel containing a liquid and I cause a movable
part of the said ammeter or voltmeter to press upon the liquid in its vessel so as to
push the said liquid until a part thereof shall overflow from the said vessel. The
amount so caused to overflow can then be measured in one of the two ways
hereinbefore referred to.

page_text: In Fig. 1 I diagrammatically illustrate the application of a liquid index to a
well known form of ammeter in which a core 1 supported by a spring 2 is sucked
into a solenoid 3. To the said core is attached a plunger 4 dipping into the
liquid 5 contained in the vessel 6. Immediately above the level of the liquid is
the orifice of the overflow pipe 7. 8 is the receptacle in which the liquid which is
caused to overflow collects and this receptacle may conveniently be marked with a
scale 9. It is obvious that the greater the current passed through the solenoid the
further will the plunger dip into the liquid and the greater will be the amount of
liquid pressed through the overflow pipe into the receptacle. The scale 9 will
show the amount of liquid so caused to overflow but if desired the scale might be
marked upon the vessel 6 in which case the deficiency in the vessel would indicate
the amount which had been caused to overflow. It is unnecessary for me to specify:
the carrying out of my invention with regard to other forms of electro-magnetic
ammeters or voltmeters as any competent engineer will know how to cause an.
overflow as aforesaid by means of the movable part of an electro-magnetic ammeter
or voltmeter.
(b.) In this, the second type of my invention, instead of employing the movable
part of an electro-magnetic ammeter or voltmeter to cause the overflow of the
liquid, I cause the liquid to overflow by means of the movable part of an ammeter
or voltmeter whose action depends upon the expansion of a solid body, the said
expansion being produced by the heat generated by the passage of an electric
current through a resistance coil or resisting part of the instrument.
Such an instrument is shown diagrammatically in Fig. 2, the said instrument
being constructed on the principle of a Cardew voltmeter. In this instrument 10 is
a thin platinum wire supported at one extremity to the fixed point 11 and having
at its other extremity the heavy plunger 12 dipping in liquid contained in a
vessel as in Fig. 1. When current passes through the wire 10 it is heated and
consequently expands in length, the plunger dipping further into the vessel and
causing more liquid to overflow the higher the degree to which the wire is heated.
As the wire expands in length in proportion to the heat generated in it and as the
said heat varies with the electro-motive force, as in an ordinary Cardew voltmeter,
it is obvious that the amount of liquid caused to overflow will give a record of the.
maximum electro-motive force which the current traversing the wire has attained
during any given period.
It is unnecessary to show how other ampere or volt meters depending on the
expansion of a solid through the heat generated by a current may be made self-
recording by means of the adaptation of a liquid index, as, after what has been
stated, such will be obvious to any competent electrical engineer.
(c.) In this, the third type of my invention, instead of causing the overflow of
the liquid to be brought about by the expansion of a solid through electrically
generated heat, I cause it to be brought about by the expansion of a liquid, the
said expansion being similarly produced.
This type of my invention is diagrammatically illustrated in Fig. 3 in which 13 is
a vessel having an upwardly extending tube 14 and containing a liquid 15. 16 is
the overflow pipe as before and 17 is a heating resistance in the body of the liquid.
As current passes through this resistance it becomes heated more or less and:
heating and consequent expansion of the liquid takes place with overflow as before:
described, the quantity of liquid caused to overflow giving as before a record of
the maximum current or electro-motive force during any given period.
It is obvious that as the maximum movement of the movable part of the ammeter
or voltmeter in one direction will cause maximum current or electro-motive force
to be recorded so maximum movement in the other direction will cause the
minimum current or electro-motive force to be recorded if a second liquid index be.
employed.
Figures 4, 5 and 6 illustrate diagrammatically cases corresponding with those:
illustrated in Figures 1, 2 and 3 but adapted to give minimum as well as maximum
records according as one or other of the two liquid indexes employed is affected...

page_text: In Figure 4, where the instrument is assumed to be set for a mean or normal
current, 18, 19 are two pins attached to the rod 20 connected with the core 1.
Pin 18 presses upon the upper surface of the maximum lever 21 which turns on
the fulcrum 22, whilst pin 19 presses on the under surface of the minimum lever 23
which turns on the fulcrum 24. It will be seen that increase of current will cause
the light plunger to dip further into the liquid of the maximum recording device M ;
whilst decrease of current will cause the other light plunger to dip further into the
liquid of the minimum recording device N.
In Figure 5, which corresponds with Figure 2, and in which it is assumed that
the instrument is set for a mean or normal electro-motive force, 10 is the wire
through which the current passes as before and 25 is a similar wire through which
no current passes: whilst 26 is a spring for putting the necessary strain on the two
wires. 27 is a lever to which wires 10 and 25 are attached, the point 28 at which
wire 25 is attached serving as a fulcrum for the said lever. It will be seen that
increase of electro-motive force will cause wire 10 to expand and the plunger to
dip further into the liquid of the maximum device M, whilst decrease of electro-
motive force will cause wire 10 to shrink and the other plunger to dip further into
the liquid of the minimum device N.
In Figure 6, which corresponds with Figure 3, 29 is a lever pivotted at 30 to the
upright 31 attached to the side of the vessel containing the expansible liquid. This
vessel which is full of liquid has a tight flexible cover 32 resembling that of an
aneroid barometer box which cover is articulated to lever 29 by means of the
link 33. This instrument being set for a mean current it is obvious that increase
of current will cause increased dipping of the plunger in the maximum device M,
whilst decrease of current will cause increase of dipping in the minimum device N.
It is obvious that in the case of instruments giving both minimum and maximum
records the instrument is set for a mean or normal current or electro-motive force
as the case may be.
In practice the resetting of the instrument inay be effected by decanting the
liquid which has overflowed into vessel 8 back into the vessel 6. One convenient
way of effecting this would be by connecting the top of vessel 8 with overflow
pipe 7 by means of a rubber tube so that all that would be required to be done
would be to tip vessel 8 upside down so that its contents might flow back into
vessel 6.
In connection with my invention I may, when desired, employ any of the known
means of compensating for temperature errors and or of shielding the instruments
from external variations of temperature.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
-
1. The combination of an electro-magnetic ammeter (or voltmeter) and a liquid
index, substantially as and for the purpose set forth.
2. The combination of an ammeter (or voltmeter), whose action depends upon
the expansion of a solid, and a liquid index, substantially as and for the purpose
set forth.
3. The combination of an ammeter (or voltmeter), whose action depends upon
the expansion of a liquid, and a liquid index, substantially as and for the purpose
set forth.
Dated this 15th day of January 1890.
For the Applicant,
J. G. LORRAIN, M. Inst. E.E., M.I. Mech. E., &c.,
Chartered Patent Agent.