AN IMPROVED MEter for ELECTRIC CURRENTS
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and W
Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents for an Invention of AN IMPROVED MEter for
ELECTRIC CURRENTS communicated to him from abroad by Lucien Hours-
Humbert, of Besançon, France
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
'
at the Office of the Commissioners of Patents on the 20th November 1883.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents,
"AN IMPROVED METER FOR ELECTRIC CURRENTS [communicated to him from
abroad by Lucien Hours-Humbert, of Besançon, France]
"
,
This Invention relates to a meter for the electric current, whether employed for
lighting or other purposes, and is based on the measurement of the time during
which the current passes through any or all of the lamps or other apparatus in the
working circuit. By this meter the aggregate several periods of time during
which the current traverses the several apparatus in the working circuit is
ascertained in an automatic manner, without reference either to the mode of
opening or closing the working circuit or the times at which this takes place.
When employed with an incandescence installation for instance one or more of the
lamps may be cut out at will the indications of the meter being at all times
proportional to the number of lamps in service."
'
The apparatus consists essentially of a contact arm rotated by clock work at any
suitable speed (preferably at the rate of 10 revolutions per hour or one in 6 minutes)
said arm closing at each revolution the circuits of as many sub-derivations as there
are lamps or apparatus to be measured. The circuits thus closed are sub-derivations
of the primary derivations or branches wherein are placed the lamps or other
apparatus which are in multiple arc as usual.
Thus each time that the arm closes the circuit through a sub-derivation a portion
of the current passes through said sub-derivation provided that the current is then
traversing the lamp or apparatus placed in the primary derivation to which said

page_text: sub-derivation corresponds each passage of the current through a sub-derivation
advances to the extent of one tooth, one of the wheels of the registering train
which it will be readily understood will thus aggregate the several periods of time
during which the several lamps or apparatus are in work.
In order that the Invention may be more readily understood I will proceed to
describe it with reference to the accompanying drawings which illustrate an
example of the Invention as applied to an installation for electric lighting by
incandescence
Figure 1 shows a face view of the contact disc and figure 2 an edge view of the
same. Figure 3 is a diagram showing the arrangement of the installation. The
same letters of reference are used to denote the same parts in the three figures.
The
A, B, C, D, E F, figure 3 are the lamps arranged in multiple are by being
placed in derivations a, b, c, d, e, f, of the main leads x y. From these
derivations a, b, c, d &c. are respectively taken sub-derivations a¹, a³, b¹, b³, cl cs
dds &o. The wires a b c & which may be replaced by a single wire communi-
cating with the main lead X are all connected to one of the terminals of an
electro-magnet Z whose other terminal communicates with the radial arm o.
wires a³, b³, c³, d³ & are respectively connected with the contacts a², b², c² dª &°
which may either consist of springs or their equivalent or levers which respectively
press on studs a b, c d &° at the moment of contact as shewn in figures 1 and 2.
These contact levers or springs a b c d² & are so arranged that the arm o will
come in contact with them in succession as it is rotated at a uniform speed (say
one revolution in every six minutes) by means of clockwork contained in box H
figure 2.
Each time that the arm o comes in contact with each one of the levers a², b³, c² &c
that corresponds to a lamp or other apparatus that is for the time being in work
the circuit in the corresponding sub-derivation a³ ³ ³ & will be closed and the
electro magnet Z will consequently be caused to attract its armature j figure 3
whereby the registering mechanism will be advanced to the extent of one tooth.
When however the arm o comes in contact with a² for example which corresponds
with a lamp A that is for the time being cut out of circuit no current will pass
through the electro magnet Z since there is no current passing through the primary
derivation a in which the lamp is placed and the registering mechanism will not
consequently be operated.
It will thus be seen that at every revolution of arm o in the direction of the
arrows a figures 1 and 3 the current will only pass in the sub-derivations of those
lamps or apparatus which are in work, and that consequently the registering
mechanism will only advance as many teeth as there are lamps or apparatus in
work. Such an arrangement it will be seen reduces the number of parts of the
registering apparatus to a minimum, inasmuch as the current acts almost directly
upon the registering mechanism, and the accuracy of the measurement is quite
independent of the distance between the contacts a³ b² c² d* & so that it is even
unnecessary that these contacts should be at equal distances apart. The resistance
of the electro-magnet Z should be sufficient to permit the passage of only a very
small portion of the current so as not to materially alter that passing through the
working circuit.
With this system of meter no fraud is possible inasmuch as the operation of the
registering mechanism is effected by the passage of the working current itself.
I have not described any particular construction of clockwork nor of the
registering mechanism the operation of the meter being independent of the wheel
work and of the particular arrangement of the contacts on the disc O.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Patent Office on the 20th May 1884.
ALEXANDER MELVILLE CLARK, of the firm of A. M. and W. Clark of 53 Chancery
Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents
"AN IMPROVED METER FOR ELECTRIC CURRENTS." A communication to me from
abroad by Lucien Hours-Humbert, of Besançon, France
This Invention relates to a meter for the electric current, whether employed for
lighting or other purposes, and its operation is based on the measurement of the
time during which the current passes through any or all of the lamps or other
apparatus in the working circuit. By this meter the aggregate of the several
periods of time during which the current traverses the several apparatus in the
working circuit is ascertained in an automatic manner, without reference either to
the mode of opening or closing the working circuit or the times at which this
takes place. When employed with an incandescence installation for instance one or
more or even the whole of the lamps may be cut out at will the indications of the
meter being at all times proportional to the number of lamps in service.
The apparatus consists essentially of a contact arm rotated by clock work at any
suitable speed (preferably at the rate of 10 revolutions per hour or one in
6 minutes) said arm closing at each revolution the circuits of as many sub-
derivations as there are lamps or apparatus to be measured. The circuits thus
closed are sub-derivations of the primary derivations or branches wherein are
placed the lamps or other apparatus which are in multiple arc as usual.
Thus each time that the arm closes the circuit through a sub-derivation, a
portion of the current passes through said sub-derivation provided that the current
is then traversing the lamp or apparatus placed in the primary derivation to which
said sub-derivation corresponds. Each passage of the current through a sub-
derivation advances to the extent of one tooth, one of the wheels of the
registering train which it will be readily understood will thus aggregate the
several periods of time during which the several lamps or apparatus are in work.
In order that the Invention may be more readily understood I will proceed to
describe it with reference to the accompanying drawings which illustrate an
example of the Invention as applied to an installation for electric lighting by
incandescence.
Figure 1 shows a face view of the contact disc and figure 2 an edge view of the
same. Figure 3 is a diagram showing the arrangement of the installation. The
same letters of reference are used to denote the same parts in the three figures.
A, B, C, D, E, F, figure 3 are the lamps arranged in multiple arc by being placed
in derivations a, b, c d, e, f, of the main leads X Y. From these derivations
a b'cd & are respectively taken sub-derivations a¹, a³, b¹, 'b³, c¹ c³ d' d³ & The
wires a¹ b¹, c¹ & which may be replaced by a single wire communicating with the
main lead X are all connected to one of the terminals of an electro-magnet Z whose
other terminal communicates with the radial arm o. The wires a³, b³, c³, d³ &° are
respectively connected with the contacts a, b, c, d & which may either consist
of springs or their equivalent or levers which respectively press on studs
a, b, c, d, & at the moment of contact as shown in figures 1 and 2. These
contact levers or springs a³, b, c, d, &° are so arranged that the arm o will come
in contact with them in succession as it is rotated at a uniform speed (say one
revolution in every six minutes), by means of clockwork contained in box H
figure 2.
Each time that the arm o comes in contact with each one of the levers

page_text: a², b, c & that corresponds to a lamp or other apparatus that is for the time
being in work, the circuit in the corresponding sub-derivation a³, bs, c³ & will be
closed and the electro magnet Z will consequently be caused to attract its armature j
figure 3 whereby the registering mechanism will be advanced to the extent of one
tooth. When however the arm o comes in contact with a² for example, which
corresponds with a lamp A that is for the time being cut out of circuit, no current
will pass through the electro magnet Z, since there is no current passing through
the primary derivation a in which the lamp is placed and the registering
mechanism will not consequently be operated.
It will thus be seen that at every revolution of arm o in the direction of the
arrows a figures 1 and 3, the current will only pass in the sub-derivations of those
lamps or apparatus which are in work, and that consequently the registering
mechanism will only advance as many teeth as there are lamps or apparatus in
work. Such an arrangement it will be seen reduces the number of parts of the
registering apparatus to a minimum, inasmuch as the current acts almost directly
upon the registering mechanism, and the accuracy of the measurement is quite
independent of the distance between the contacts a b c d & so that it is even
unnecessary that these contacts should be at equal distances apart. The resistance
of the electro-magnet Z should be sufficient to permit the passage of only a very
small portion of the current so as not to materially alter that passing through the
working circuit.
With this system of meter no fraud is possible inasmuch as the operation of the
registering mechanism is effected by the passage of the working current itself. I
have not described any particular construction of clockwork nor of the registering
mechanism the operation of the meter being independent of the wheel work and
of the particular arrangement of the contacts on the disc O.
Having described, the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is :
1 In a meter for totalising the periods of time during which the electric current
traverses the different lamps or apparatus in the working circuit the combination
of a clock actuated rotating contact arm and of a circle of contacts, the arm and
the contacts respectively communicating with sub-derivations of the primary
derivations or branches whereon are placed the lamps or other apparatus
substantially as herein specified.
2nd The combination with a clock actuated rotating contact arm, and a circle of
contacts respectively connected as described with sub-derivations of the primary
derivations or branches on which the apparatus are placed of an electro-magnet
and a registering apparatus, the whole being so combined that the electro-magnet
will advance the registering mechanism every time the contact arm closes the
circuit through the sub-derivation corresponding to an apparatus in work
substantially as shown and described for the purpose specified.
In witness whereof I the said Alexander Melville Clark have hereunto set my
hand and seal this Twentieth day of May A.D. 1884.
CT AD IZ