Year: 1888

page_text: Date of Application, 7th Jan., 1888
Complete Specification Left, 8th Oct., 1888
Complete Specification Accepted, 9th Nov, 1888
I, THOMAS PARKER of Elwell Parker Limited Commercial Road Wolverhampton
in the County of Stafford Electrical Engineer, do hereby declare the nature of this
invention to be as follows:
This Invention relates to a new or improved Electric Meter.
In constructing a meter according to these Improvements I employ two metallic
thermometers connected in opposition to each other by a pivoted rod in such a
manner that any variation of temperature to which both thermometers are equally
exposed will give no motion to the rod but so also that if one thermometer is exposed
to a greater or less temperature than the other motion will be imparted to the rod.
This arrangement eliminates any disturbing effect of varying atmospheric temperature
to which both the thermometers may be exposed.
One of the thermometers is exposed to the heating effect of a current of electricity
in a coil of wire or in a conductor forming part of an electrical circuit so that any
variation in the current will produce a variation in the heating effect which will
correspondingly influence that thermometer and produce angular motion of the
pivotted bar connected thereto.
Upon the rod a pawl
pinned and arranged so as to be capable of engaging with
the teeth of a ratchet wheel.
If therefore, the rod is depressed or moved to its zero position at regular intervals,
angular motions in one direction are given to the ratchet wheel and each of these
angular motions will be proportionate to the current during that interval. If also,
the teeth of the ratchet wheel are graduated to represent ampères and the rod is
depressed at one minute intervals the number of teeth occupying the angle through
which the wheel moves will equal ampère-minutes of current.
The rod is depressed by clockwork and by preference by means of an electrically
driven clock so as to obviate the necessity for rewinding. The motion of the wheel is
transmitted by suitable apparatus to devices for registering indicating or recording
the values of the current.
Dated this 5th day of January A.D. 1888.
WILLIAM E. HEYS,
Agent for the Applicant.

page_text: I, THOMAS PARKER of Elwell-Parker Limited Commercial Road Wolverhampton
in the County of Stafford 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 :-
This Invention relates to a new or improved electric meter.
In constructing a meter according to these Improvements I employ two metallic
thermometers connected in opposition to each other by a pivotted rod in such a
manner that any variation of temperature to which both thermometers are equally
exposed will give no motion to the rod but so also that if one thermometer is exposed
to a greater or less temperature than the other, motion will be imparted to the rod.
This arrangement eliminates any disturbing effect of varying atmospheric temperature
to which both the thermometers may be exposed.
One of the thermometers is exposed to the heating effect of a current of electricity
in a coil of wire or in a conductor forming part of an electrical circuit so that any
variation in the current will produce a variation in the heating effect which will
correspondingly influence that thermometer and produce angular motion of the
pivotted bar connected thereto.
Upon the rod, a pawl is pinned and arranged so as to be capable of engaging with
the teeth of a ratchet wheel.
If therefore, the rod is depressed or moved to its zero position at regular intervals,
angular motions in one direction are given to the ratchet wheel and each of these
angular motions will be proportionate to the current during that interval. If also the
teeth of the ratchet wheel are graduated to represent ampères and the rod is
depressed at one minute intervals the number of teeth occupying the angle through
which the wheel moves will equal the number of amepère minutes of current.
The rod is depressed by clock work and by preference, by means of an electrically
driven clock so as to obviate the necessity for re-winding.
The accompanying diagram will enable my Invention to be more clearly understood.
A and A are two metallic thermometers constructed of two dis-similar metals such
as steel and brass and formed in a curve coil or spiral as is well understood and so
that the curve coil or spiral tends to open out or straighten with an increase of
temperature. As illustrated in the diagram the current or a known part of the
current is supposed to pass through the thermometer A and will heat it more or less
according to the strength of the current. The heat so developed tends to open out or
straighten the thermometer as before described. Each of the thermometers is fixed
at its outer end, and at its inner end is connected by any suitable means to the pivotted
rod B, and they are opposed so that an increase of temperature similarly acting
upon both thermometers will result in an equal stress on each side of the rod B which
consequently will not be moved. If however one of the thermometers is heated by the
passage of a current of electricity, the rod will be subject to unequal stresses and will

page_text: consequently be moved through an angle determined by the difference of temperature.
D is a pawl mounted upon the rod B and engaging with the ratchet wheel C E is a
disc rotated by clockwork and carrying the pin F; H H are the lead and return
wires to the thermometer. The action of the apparatus has been hereinbefore
described and it is therefore only necessary to add that in the diagram, the dotted lines
are supposed to represent a position of the rod and pawl when a current is passed
through the thermometer A. The wheel E revolving at a uniform rate will by the
contact of the pin thereon with the rod, bring the rod and pawl into the position
indicated by full lines once for every revolution and in doing so will consequently
move the ratchet wheel through an angle determined by the current. In the reverse
motion of the rod the pawl will slip over the teeth of the ratchet wheel without
originating motion. The thermometer may obviously be heated by convection from a
neighbouring coil or conductor through which the current to be measured is passing
instead of by the passage of the current directly through it.
The motion of the ratchet wheel is transmitted by suitable gearing to devices for
counting or indicating the number of its revolutions or for otherwise indicating
registering or recording the value of the current.
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) An electric meter constructed and arranged, substantially as hereinbefore
described.
(2) In an electric meter; the combination of two metallic thermometers with a
ratchet wheel and pawl, means and devices for operating the ratchet wheel by the
thermometers, and a clock driven device for moving the pawl at regular time intervals;
substantially as hereinbefore described.
Dated this 4th day of October A
1888
WILLIAM E. HEYS,
Agent for the Applicant.