Improvements in Electric Meters.
Year: 1896

page_text: Date of Application, 11th Nov., 1896-Accepted, 21st Aug., 1897
COMPLETE SPECIFICATION.
Improvements in Electric Meters.
I, JOHN FRANCIS DE BAUW, of 133, Chaussée d'Ixelles, Brussels, Belgium,
Manufacturer, 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 an electric meter which is adapted to record the smallest
consumption of current with considerable accuracy, whilst not requiring any
appreciable consumption of current for the purpose of operating the recording
apparatus, and which shall be capable of being adjusted to suit the potential of the
current.
This meter consists essentially of an ammeter which is included in the electric
circuit and the pointer of which is connected to a dial registering-apparatus of ordinary
construction by means of a special apparatus that forms the characteristic feature of
the present invention. As soon as a current passes into the circuit, this special
apparatus is disengaged by the pointer of the ammeter and, as the result of the
expansion of a spring, causes the pointers of the registering dials to advance through
an angle or angles corresponding to the quantity of electricity that passes, during each
minute or fraction of a minute, through the ammeter.
In order to enable my invention to be clearly understood, I will proceed to describe
the saine with reference to the accompanying drawings, in which
Fig. 1 is an elevation of the meter as seen from the left-hand side;
Fig. 2 is a similar view of the same as seen from the right-hand side, certain parts
being omitted for the sake of clearness ;
Fig. 3 is a plan;
Figs. 4 and 5 are views showing certain details of the apparatus, and
Fig. 6 is an underside-view of the meter.
I, I are the vertical bobbins of the ammeter through which passes the current which
is to be measured, and U is the inner bobbin through which passes a shunt or derived
current as in electrodynamoters of this kind. The inner bobbin U rocks on an axle u
carried by journals in bearings X and X. G is the pointer fixed on the axle u so
that the rotation of the latter under the influence of the passage of the currents in the
ammater and shunt bobbin depresses the point of the pointer proportionately to the
product of the intensity of the said currents by which the intensity of the main
current may be easily calculated. The pointer G is prolonged beyond the axle u,
and from the end of its prolongation there is suspended a counterweight J, which may
be immersed in a liquid, as shown. Another counterweight J1, which is adjustable
vertically and laterally by means of screws jj, and is suspended from the axle u,
enables the position of the point of the pointer when no current is passing in the
circuit, to be adjusted. is the conductor of electricity which conveys the positive
current to the ammeter, and is the conductor by which the current leaves the
ammeter to go to the lamp or lamps or other place where it is to be used. 23 are
the conductors for the negative current the inner bobbin U being shunted between
and 3. A thin wire a connected to the couductor acts as a shunt through which
a small portion of the positive current passes through a bobbin or solenoid (hereinafter

page_text: referred to as a bobbin) A having a hollow core A which constitutes the magnetic
field of the apparatus that operates the registering apparatus. Into the hollow of the
core A¹ there enters one end of an armature B of soft iron fixed at its other end to
one end of a horizontal rod C preferably of copper, the other end of which is
connected to a support Q by means of a small piece c of flexible steel constituting a
spring.
When a current passes through the bobbin A, the armature B is alternately
attracted into the hollow of the said bobbin and forced back out of the bobbin against
a rubber stop b, thereby imparting to the rod C a to-and-fro motion about its
support Q. This oscillation of the armature B is caused by a contact-device r
hereinafter described, which alternately interrupts and re-establishes the circuit
through the bobbin, acting in conjunction with the spring c, which draws back the
armature out of the bobbin whenever the circuit is interrupted. Upon the rod C near
its flexible attachment c there is jointed a pawl H the free end of which is engaged
and pressed by a spring à between the teeth of a ratchet-wheel D provided with a
detent D¹ and keyed at the top of a short vertical axle around which is coiled a spiral
spring enclosed in a cylinder à (see Fig. 2). Each time the armature B is attracted
into the bobbin A, the oscillation of the rod C pushes the pawl H against the ratchet-
wheel D and causes the latter to move forward through the distance of one tooth and
thereby compresses the spiral spring to a corresponding extent.
By means of suitable gearing the spiral spring of the cylinder d in expanding
rotates a toothed pinion e (Fig. 2) formed on the lower portion of a vertical shaft F
whose lower end is journalled in the base-plate of the meter and whose upper end
turns in an aperture in a small support fixed to the frame of the registering dials.
On the shaft Fabove the pinion e there is keyed a circular disc el and around the
edge of this disc el there is fixed, by means of the long side of its right angle, a
small sheet of metal E which is cut in the shape of a right-angled triangle arranged
concentrically to the shaft F in such a manner that the short side of the right angle
of the triangle is vertical whilst the long side is bent to a circle so that both ends
meet.
The point of the pointer G is directed so as to touch the cylinder described by the
short side of the triangle E when the dise e turns, and, by means of its adjustable
counter-weight J¹, the position of the pointer G is regulated in such a manner that
when no current is passing in the apparatus the height of its point will coincide
exactly with the top of the short side of the triangle E. The pointer G is provided
near its point, on the side turned towards the shaft F, with a small stop, which
comes into contact with the surface of the triangle E when the disc e turns. In
the support of the axle w there is pivoted the upright of a cross stay T, whose
arm passes above the pointer G and makes with it a very acute angle, and which is
constantly pressed towards the shaft F by means of a small spiral or coiled
spring
The arm of the stay T extends horizontally nearly to the point of the pointer G
and ends in a dependent arm T bent to the are described by the point of the pointer
when it is depressed by the passage of a current.
The pointer G is provided, near its point and at the side turned away from the
shaft F, with a small catch g, which rests against the depending arm T of the stay
and slides along the latter when the pointer is depressed. From the level of the
horizontal arm of the stay T to its upper end the diameter of the shaft F is reduced
and on its thinner portion there is mounted a small perforated spring f, which rests
on the shoulder formed by the thinning of the shaft and the two limbs of which are
curved upwardly. Upon the curved limbs of the spring f there rests a toothed
wheel fixed on the lower part of a sleeve V that is free to turn on the thin portion
of the shaft F and the top of which carries a worm gearing into a vertical wheel k
that drives the whole of the clockwork of the registering-dials.
The horizontal arm of the stay T is provided near its end, on the side turned towards
the shaft F, with a small laterally projecting catch that engages between the teeth
of the wheel V and thereby prevents the rotation of the latter. As shown in Fig. 3,

page_text: this catch may be formed by a small spring the projection of which is capable of
adjustment by means of a screw.
The vertical shaft F driven by the expansion of the spiral spring in the cylinder d,
as above stated, carries at its upper end a toothed wheel O, which, through the medium
of pinions and toothed wheels 01, 02, and 0%, transmits the rotary motion of the
shaft F to a small vertical shaft I, carrying a fly L. This shaft L is also provided
under the fly with a star N composed of light radial rods.
To the internal bobbin U there is fixed a bent or cranked rod M which shares the
oscillations of the said bobbin and consequently of the pointer G. When no current
is passing in the ammeter the free end of the rod M passes through the plane of the
branches of the star, and thus prevents the rotation of the latter, the shaft L, the
fly L, the shaft F, and, consequently, stops the expansion of the spring in the
cylinder d.
When a current passes in the circuit, the inner bobbin U, in oscillating, depresses
both the rod M and the pointer G, and the expansion of the spring immediately
rotates the vertical shaft F, which moves with it in its rotation the triangle E, the
star N, and the fly L.
The spring is wound up once for all when the apparatus is set, and during the
working of the meter its expansion should always be exactly compensated by the
tension produced by the oscillations of the armature, as above described.
As the point of the pointer, when in its highest position, is situated exactly on a
level with the top of the short side of the triangle E, therefore as soon as it is
depressed, however small such depression may be, its lateral stop g will necessarily
come into contact with a part of the curved surface of the triangle E when the latter
rotates with the shaft F, and the more the pointer is depressed by the strength of the
current passing in the circuit, the greater will be the surface of the triangle E which
will come into ccntact with the stop g', and the longer will such contact last. As
soon as the vertical edge of the triangle E, in revolving, meets the stop g', which has
an inclined surface on that side, it will push it back outwardly until its apex or edge
rests on the curved surface of the said triangle, and at the same time it also pushes
back the pointer G, whose body pushes back in turn the stay T and disengages the
stop t of the latter from the teeth of the wheel V' which is then caused to share the
rotation of the shaft F. With it there rotates the sleeve V whose worm v then
rotates the toothed wheel k that drives the clockwork of the registering dials K.
As soon as the stop g' of the pointer G ceases to be in contact with the surface of the
triangle E, the stay T is returned by its spring towards the shaft F, and returns the
pointer to its original position, its catch engaging anew between the teeth of
the wheel V and stopping the latter, as also the sleeve V, the worm v, and the
wheel that operates the registering pointers. The consequence is that the
registering pointers record the passage of the current only during the contact of
the triangle E with the stop of the pointer G.
If, therefore, the spring in the cylinder d is adjusted in such a manner that the
disc e and the triangle E will make one revolution per minute, for example, the dials
will record in the course of each minute a greater or less consumption according as
the pointer be more or less depressed before its stop comes into contact with the
triangle-that is to say, a consumption proportionate to the strength of the product
of the currents passing in the bobbins Il and U, or simply proportional to the current
in the circuit, as the current in the bobbin U is practically constant with a constant
E.M.F. between the leads, and depends upon the proper resistance of the bobbin.
When the outer surface of the triangle E is smooth, the meter records for the
whole of the minute a uniform consumption according to the strength of the current
at the moment at which the stop of the pointer comes into contact with the triangle,
but an exact record for any desired fraction of a minute may be obtained by using a
triangle whose surface presents (as shown in Fig. 5) a succession of angular grooves
connected together by straight planes and described according to the curve traversed
by the point of the pointer in moving up and down on the surface of the triangle.
Every time that during the rotation of the triangle E, the stop gl of the pointer

page_text: pass beyond the top of one of the grooves, it will lose contact with the triangle, and
if the strength of the current have varied during its contact with the inclined portion
of the groove, the pointer will be free to ascend or to descend in proportion before
the spring of the stay have moved the stop gl back into contact with the surface of
the next following groove.
If, therefore, for instance, the triangle when making one revolution per minute,
has its surface divided into thirty successive sections or angular grooves, the pointer
will be able to move down or up every two seconds if variations occur in the strength
of the current.
In order that the apparatus may be able to serve for recording the consumption of
currents of different potentials, the spring rod C of the armature carries a weight in
the form of a runner or traveller C, whose position can be adjusted on the said rod
so as to vary the resistance of the armature to the current of the bobbin A in proportion
to the potential of the current passing through the apparatus. The inore this
potential rises, the nearer the weight c' should be moved towards the armature.
The current taken as a shunt to the conductor ¹ for energizing the bobbin A, after
having passed through the latter, passes to the terminal R and thence to the upper
contact of a pair of contacts fixed respectively to levers z, z pivoted to a block z
which may be made to oscillate forwards or backwards by means of a handle P for the
purpose of regulating the relative position of the contacts. The latter are preferably
covered with platinum with the object of preventing oxidation.
A wire (Fig. 6) connects the lower contact with the negative pole of the
apparatus.
The upper surface of the wheel D2 that drives the pinion of the vertical shaft F is
provided around its periphery with a rack having angular vertical teeth between
which rest, one behind the other, fingers 23 projecting under the levers z and z¹ in
such a manner that, when the wheel D² rotates in consequence of the expansion of
the spring, the inclined surface of its angular teeth raises the fingers, which fall
back, one after the other, to the bottom of the following tooth, and when the second
finger, fixed to the upper lever z, falls back, the first finger being already moved
forward a certain distance on the inclined surface of the following tooth, the upper
contact will touch the lower contact r, thus reestablishing the circuit through the
bobbin.
Having now particularly described and ascertained the nature of the said.
invention and in what manner the same is to be performed I declare that what I
claim is:-
1. In an electric meter, the combination of a solenoid or bobbin which has a hollow
core and through which passes a shunt current from the main current, means for
rendering this current intermittent, a soft iron armature one end of which enters the
hollow centre of the bobbin, and the other end of which is fixed to one end of a flexible
rod fixed at its other end to a suitable support, and a spring pawl fixed to the said
flexible rod and engaging between the teeth of a ratchet-wheel keyed on a shaft
around which is coiled a spring, the entire arrangement being such that the passage
of the current in the bobbin produces a to-and-fro movement of the armature and of
the flexible rod, whose pawl, each time the annature is attracted by the bobbin,
causes the ratchet-wheel to partly rotate, thereby producing a proportionate tension
in the spring coiled round the said shaft.
2. In an electric meter, the combination of an ammeter, a shunt bobbin, one or
more recording dials operated by suitable gearing actuated by a worm free to rotate
around a vertical shaft that is rotated by the expansion of a spring, a circular disc
fixed on the said vertical shaft, a plate cut out in the form of a right-angled triangle
and having the long side of its right angle curved to a circle and fixed to the periphery
of the disc, a stop having an inclined surface projecting from the side of the pointer
of the ammeter and touching the cylindrical surface described by the rotation of the
triangle, means for stopping the rotation of the vertical shaft and of the triangle

page_text: when the passage of the current through the ammeter is interrupted, means for
stopping the rotation of the worm on the said vertical shaft when the pointer is not
in contact with the surface of the triangle, means for rotating the vertical shaft and
the triangle as soon as current passes into the ammeter, and means for rotating with
these latter the worm that operates the registering devices when the stop on the side
of the pointer of the ammeter eomes into contact with the surface of the triangle,
substantially as described and shown and for the purpose specified.
3. In an electric meter, apparatus as described in Claim 2, in which the triangle
has its surface divided into a series of angular grooves parallel to the arc described by
the free end of the pointer of the ammeter under the influence of the passage of a
current, substantially as described and shown and for the purpose specified.
4. An electric meter constructed, arranged, and operating substantially as
herein before described with reference to and shown in the accompanying drawings.
Dated this 10th day of November 1896.
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.