Improvements in Electricity Meters.
Year: 1892

page_text: Date of Application, 27th June, 1892-Accepted, 1st Oct., 1892
COMPLETE
SPECIFICATION.
. Improvements in Electricity Meters.
HERBERT WOODVILLE MILLER of 2 York Mansions, Earls Court, London, S.W.
County of Middlesex 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 :-
My invention has for its object improvements in electricity meters in which the
registration is obtained by measuring the difference in speed between 2 clocks such
as in the well known Aron meter or in the Oulton-Edmundson meter. In these
forms of meters should one of the clocks stop from any cause, the other clock
continues to work and moves the registration dials either forwards or backwards
thus destroying the record of the meter; and further when no current is passing
through the meters the 2 clocks being adjusted to work at the same speed or in
other words synchronised, so that there shall be no registration on the recording
dials, but if the 2 clocks do not remain synchronised there will be a movement of
the recording dials either forwards or backwards although no current is passing
through the meters:
According to my invention I add to new or existing meters of these types
automatic devices which in the event of one of the clocks stopping will stop the
second clock, thus preventing the record of the meter being lost and further I
provide a device which will disconnect the registration train of wheels from the
lockwork during the time that no current is passing through the meter.
I will now describe one way of carrying out my invention as applied to an Aron
meter and which will be more clearly understood by reference to Figures 1, 2 and 3.
On the spindles C C of the second toothed wheels D D of the clocks A and B
I mount other toothed wheels E E loose on the spindles, and I join them to the fixed
toothed wheels D D'either by means of a small spiral spring or a straight. piece of,
thin flexible spring steel as shewn at FF one end being fixed to the hub of the
fixed wheel and the other end being fixed to a pin on the loose wheel, pins G¹ G¹
are also fastened in the fixed wheels and situated a little behind the position of the
pins on the loose wheels, so that if the loose wheels are stopped whilst the fixed
wheels are revolving, these pins come into contact with each other very quickly
and further rotation of the fixed wheels is prevented; and if the loose wheels are
released they will fly back to their original positions under the action of the
springs.
Mounted in the frame work of the clocks I provide two rocking levers HH
carried on a spindle, one end of each of these levers is provided with a pawl which
fits in the teeth of the loose wheels, E E and the other end of each of these levers
is projected so that it comes into contact with the pendulum escapement lever I. I
during a portion of the stroke of this lever. The two rocking levers H H are so
arranged that the pendulum escapement lever of clock A moves the rocking lever
which releases the pawl from the loose wheel E of clock B'and vice versa with the
clock B.
:
The action of the rocking levers is as follows; when both clocks are at work, at
a portion of the stroke of each of the pendulum escapement levers, the pawls of the
rocking levers H H are lifted out of the teeth of the loose wheels E E, these
wheels are then free to revolve with the wheels D, D, being carried round by the
springs FF; when the further movement of the pendulum escapement levers allows
the rocking levers H, H to fall and lock the wheels E E, these wheels can remain
stationary for a time, due to the bending of the springs F F, whilst the wheels D D
continue moving; but the pawls are again quickly released by the action of the
pendulum escapement.lever.

page_text: Should however one of the clocks stop, the pendulum escapement lever of this
clock will no longer release the pawl in the-wheel-of the other clock, this other
clock will continue working for. one or two,beats of the pendulum, depending on the
distance apart of the pins G, G, until the pins come into contact and stop further
movement of the clock,, both clocks are then stopped.
I find it better to use such an arrangement as described in, which the rocking
levers are only in contact with the clock, escapements during a portion, of. their
stroke, as I find that with an arrangement which is continuously connected with the
clockwork adds friction to the movement of the clocks, and interferes with their,
proper working.
In order to disconnect the recording train of wheels from the clocks, I fix to
the spindle of the differential wheel a toothed wheel K and close to this but loose
on the spindle I put a second toothed wheel K' and mount on the 'sleeve of this
wheel one of the pinions and toothed wheels of the recording train of wheels, these
two wheels K K¹I call the clutch wheels. By means of a suitable lever L having
a förk at the end where it comes in. contact with the loose clutch wheel 'K', I can
throw the wheel K¹ into. gear with the wheel K or by moving the lever L'away from
the fixed wheel K, the clutch wheel 'K' is thrown out of gear with the wheel K;
thus either connecting or, disconnecting the recording train of wheels with or from
the clockworks.
The fork on the end of the lever L is arranged to fit round part of the sleeve on
which the loose clutch wheel K', is mounted and allows this wheel & the pinion and
toothed wheel to revolve freely; two 'shoulders are formed on the sleeve on each
side of the fork so that when the lever and fork 'move backwards or forwards the
fork strikes one of these shoulders and the wheel K is then moved together with
the fork.
I'.
I provide a stóp against which the lever L'touchés after the clutch wheels are.
sufficiently in gear so as to prevent the, two wheels from being pushed tight against
each other; which would cause undue friction and interfere with the proper working
of the clocks.
5
3
The movement of the lever L is obtained by means of an ordinary electro-magnét
attracting an armature to which is attached the lever. I pass round the coils of.
the electro-magnet either a part or the whole of the current to be measured by the
meter, the electro-magnet is thereby magnetised and attracts is armature which
carries with it the lever L and the clutch wheels are brought into gear; when a
the current is stopped the armature is no longer attracted by the electro-magnet
and it is drawn away by the action of gravity or by a suitable spring, thereby
disconnecting, the clutch wheel K₁ and the recording train of wheels from the
clockworks.
:
Where it is necessary to make. the electro-magnet, work with a small fraction of
the total current to be passed through the meter such as for instance to work with
one ampère out of one hundred and fifty as the capacity of the meter it is better to
use a polarised electro-magnet as used in telegraphic relays.
I arrange the electro-magnet so that it has practically a closed magnetic circuit,
or shield it with iron, and fix it in a part of the meter where it will not affect the
magnetic pendulum of the meter.
: +
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) In electricity meters in which the difference in speed between two clocks,
actuated by springs or by the electric current or other motive power, is used for
measuring the consumption of electricity; the addition of automatic devices so that
if one clock stops the second clock is stopped, consisting of two rocking levers
receiving intermittent motion from the clocks, wheels with springs and pins.
substantially as and for the purpose herein described.
(2) In electricity meters as above the addition of automatic devices for

page_text: disconnecting the recording train of wheels from the clocks when no current is
passing through the meters, consisting of an electro-magnet with movable armature
with lever and fork and two clutch wheels, substantially as and for the purpose
herein described.
2005
H. W. MILLER.