Improvements in or relating to Electric Meters.
Year: 1891

page_text: Date of Application. 17th Apr., 1891
Complete Specification Left, 17th Feb., 1892-Accepted, 19th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in or relating to Electric Meters.
1. FRANCIS TEAGUE, of The Acme Electric Works, Ferdinand Street, Chalk
Farm, in the County of London, Electrical Engineer, do hereby declare the nature
of my invention to be as follows:-
In some forms of electric meters, index or integrating devices are worked by
direct mechanical connection with a rotating spindle, armature, or the like,
actuated by current force exerted through mercury contacts, in ways that are well
known.
By one part of my invention, the integrating devices are, in some cases,
mechanically disconnected from the parts actuated by the current, but are worked
by magnetic induction through a cover or case; preferably air-tight, and exhausted
of air: the case being adapted to contain the current actuating or actuated
devices. In this manner, I am enabled to avoid oxidation of the mercury, keep all
the contacts clean, and render unnecessary the re-calibration of instruments
frequently required after they have left the manufactory.
In applying my invention to practice, it may take several forms, according to
the type of ineter adopted; but the following description applies to one well known
form of electric meter which has mercury contacts.
In this meter, an annular mercury trough is mounted above the core of an electro
magnet, and a rotatable vertical spindle is suitably mounted in the centre thereof,
which is mechanically connected to a train of wheels, for the purpose of indicating
units of measurement by suitable dials and index fingers; in the well known
manner. Upon the rotatable spindle is secured an arm or arms carrying a blade
at each extremity, so arranged as to dip into the mercury and to move therewith.
A current passing radially into the mercury, causes it to revolve; and this, acting
through the arm and rotatable spindle, sets in motion the indicating train of wheels
to suitably register the current force employed. By my invention the train of
wheels is mechanically disconnected from the rotatable spindle, the latter being
suitably pivoted within an exhausted case or chamber which also encloses the
mercury trough. Upon the upper part of the spindle is secured a magnetic needle,
so as to turn with it, and between the needle and the.mercury trough is interposed
a magnetic screen adapted to screen the needle from stray lines of force emanating
from the magnet.
The magnetic screen is formed with a small hole in the centre,
to allow the spindle to pass through freely; and it also dip on the upper surface
towards the centre; so that any mercury accidentally displaced, may drain back to
the trough. The air chamber is exhausted through any suitable valve (placed in
the chamber), adapted to exclude the air.
Outside of the exhausted chamber I mount a suitably arranged train of wheels,
or integrating gear, actuated by a suitably mounted rotatable spindle, as before,
and to this second spindle 1 attach a magnetic needle or a piece or pieces of soft
iron. The latter is mounted as close to the cover of the chamber as possible, and
the magnetic needle within is similarly placed as close as may be to its cover, so
that the latter may actuate the former (and through it the train of wheels) by
magnetic induction alone; without any mechanical connection between the inte-
grating gear and the current actuating or actuated portion of the meter. The
cover is made of a non-magnetic material which is also a good non-conductor of
electricity, such as glass or vulcanite. The magnetic needle or needles may be of
any known form, convenient for the purpose, and arranged on the astatic system
if desired; while the soft iron pieces may be supported upon cardboard, mica,
or other similar material. The train of wheelwork may be mounted so as to

page_text: be removable for inspection or repair, without disturbing the remainder of the
meter.
It is also to be understood that my invention may be adapted to meters in which
the actuating or actuated parts are mechanically connected to the wheelwork or
integrating portion of the apparatus; the latter, in this case, being also enclosed in
the exhausted chamber. Or I may form a separate case or cover, with a suitable
base, to enclose the whole of any meter used, and exhaust the air from within the
said case.
This may be done through a suitable valve, as before stated, by an air-
pump and the invention is applicable to meters of other classes than those
employing mercury contacts, in order to eliminate any error arising from the
presence of air.
Dated this 17th day of Auril 1891
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Electric Meters.
I, FRANCIS TEAGUE, of the Acme Electric Works, Ferdinand Street, Chalk
Farm, in the County of London, 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 some forms of electric meters, index or integrating devices are worked by
direct mechanical connection with a rotating spindle, armature, or the like which is
actuated by current force passing or exerted through mercury contacts, in ways
that are well known.
By one part of my invention the integrating devices ore, in some cases,
mechanically disconnected from the parts actuated by the current, but are worked
by magnetic induction through a cover or case. The case is preferably air tight
and exhausted of air; the case being adapted to contain the current actuating or
actuated devices. In this manner I am enabled to avoid oxydation of the mercury,
keep all contacts clean, and render unnecessary the re-calibration of instruments
frequently required after they have left the manufactory.
In the further description of this invention reference is made to the accompanying
drawings in which
Fig. 1 is a vertical section through the upper portion of a meter, with the frame
of an integrating device combined therewith.
Fig. 2 is a vertical section through the top part of a meter which has a recessed
cover;
Fig. 3 is a similar view, and
Fig. 4 an inverted plan of modified arrangements of the magnetic needles (or
their equivalent) employed in driving the integrating train.
Fig. 5 is a section through a valve screwed into an air tight cover.
The letters refer to the same or equivalent parts throughout the figures.
Referring to Fig. 1, let a represent a case enclosing any form of meter, having
a rotatable spindle, actuated by an armature c This armature may have
mercury contacts (not shown) all forming part of the current circuit, while the
armature is acted upon by magnets. Or the spinelle & may carry one or more arm-
having blades or floats adapted to dip into an annular trough of mercury and to
move with the mercury therein when current is passing. Both these arrangement-
are well-known, and they are considered as equivalent for the purpose in view.
The rotatable spindle does not extend through the case a but is suitably pivoted
at d within the case. Upon the upper part of the spindle, and close to the inner
surface of the top of the case, is secured a magnetic needle e so as to turn with the
Spindle. Between the needle and the mercury trough, magnets, or other disturbing
portion of the apparatus is interposed a magnetic screen, adapted to screen the

page_text: needle from stray lines of force, and formed with a small hole in the centre
through which the spindle 6 will pass freely. The screen is shown as flat, and
supported on small brass pillars, but it may be dished or made funnel-shaped to
drain back any mercury displaced from its trough.
The cover of the case a is of some suitable non-magnetic material, and to the
outside of the case is mechanically secured a frame y, which contains a suitably
arranged train of wheels or integrating gear, (not shown) actuated from a suitably
mounted rotatable spindle and to this second spindle is attached an outer
magnetic needle i or a piece or pieces of soft iron. The latter needle or iron i is
mounted as close to the inner needle as possible, so that when the latter rotates by
the actuating devices of the meter, the outer needle i is also rotated by magnetic
induction only, acting through the case without any mechanical connection. The
spindles and should be placed in the same axial line.
In the section Fig. 2, the cover a of the meter is dished in the central part, and
within the recess is hung the outer needle i which actuates the train of integrating
wheels, (not shown), in a similar manner to that described with reference to Fig. 1.
The inner needle is secured to the armature spindle (as before described)
but at its ends it is turned up in a curved form close to the case a in order
that the intervening gaps between the inner needle e and the outer needle i shall
be as narrow as possible. The magnetic screen is dished so that mercury or
other displaced liquid in the meter may run back through the central hole, and
it is supported on a slight projection within the case a. In the section Fig. 3 a
pair of magnetic needles e are arranged as an astatic system upon the rotatable
spindle within the case a. On the outside of the case is suspended to the
rotatable spindle 4, (as before described), a light arm of aluminium, or other suit-
able material, carrying a small piece of soft iron i at each end the arm being
bent over to come close to the ends of the needles. The general arrangement of
the astatic system with the soft iron pieces i, i, is shown by the inverted plan in
Fig. 4.
In Fig. 5 a valve is screwed into the case or cover a, arranged to enclose the
actuating parts of the meter-with or without the integrating gear-in such a
manner as to be air tight. The air is exhausted through the valve which has a
small ball & acting to prevent a return of the air during the process of exhaustion.
After this has been completed the ball chamber is filled up with wax or other suit-
able material and a socket nut is then screwed over all and sealed.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed. I declare that what I
claim is :-
1. An electric meter having a magnetically driven integrating or recording
device, substantially as and for the purpose herein described.
2. In an electric meter, the combination of a rotatable spindle with a magnetic
needle secured thereto, substantially as and for the purpose herein described.
3. In an electric meter, the combination of a rotatable spindle pivoted entirely
within a closed case, a magnetic needle secured to the said spindle, and a magnetic
screen placed between the actuating parts of the meter and the said needle, sub-
stantially as and for the purpose herein described.
4. An integrating or recording device consisting of a frame carrying a train of
wheels and suitably marked dials with index fingers, a spindle arranged and
operating to drive the said train of wheels, and a magnetic needle or suitable piece
of soft iron secured to the said spindle, substantially as and for the purpose herein
described.
5. The combination of an electric meter having a rotatable spille entirely
enclosed within a case, a magnet attached to the said spindle and turning with it
an outer spindle adapted to work an integrating or index device and carrying near
the said magnet a magnet or piece of soft iran, and an intervening case or cover
substantially as and for the purpose herein described.

page_text: 6. The combination with an electric meter of an integrating or recording device,
inductively driven, and mechanically disconnected to the said meter or its case
except by fastenings only, substantially as and for the purpose herein described.
7. In an electric meter, the combination of an air tight cover or case with the
actuating devices contained therein, and a non-returning air valve secured to the
case, substantially as and for the purpose herein shown and described.
Dated this 17th day of February 1892.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.