IMPROVEMENTS IN ELECTRIC METEDO
Year: 1882

page_text: LETTERS PATENT to Charles Vernon Boys of Wing near Oakham in the
County of Rutland for an Invention of "IMPROVEMENTS IN ELECTRIC
METEDO"
PROVISIONAL SPECIFICATION left by the said Charles Vernon Boys at the
Office of the Commissioners of Patents on the 19th July 1882.
CHARLES VERNON BOYS of Wing near Oakham in the County of Rutland
"IMPROVEMENTS IN ELECTRIC METERS
"
In the Specifications of Patents granted to me on the 13th October 1881 N° 4472.
and on the 2nd February 1882 N° 513 I described forms of apparatus for measuring
the electricity passed through a conductor by counting the oscillations of a balance
governed by an electromagnet having its coil in the circuit of the conductor. My
present invention relates to an improved construction of apparatus of this kind,
the object which I have in view being to render it more simple and more readily
adjustable to various conditions as well as to render it more regular and efficient
in its action. For this purpose I fix on a spindle an iron bar rounded at the ends,
this bar being free to oscillate between two limbs of an electromagnet, these
limbs being circularly hollowed in the middle or having circularly hollowed pole
pieces attached to their middle. The two limbs have on them on each side of their
middles coils of insulated wire which are in the circuit, and they are connected by
iron at their ends, so that their middles close to which the bar oscillates are two
opposite magnetic polar fields. On the same spindle I fix another magnetic bar
which presents its ends towards the poles of a pair of electromagnets. These have
their coils occasionally brought into circuit for the purpose of giving an impulse to
the oscillating armature by the following arrangement. A pair of springs are
provided with contact points which are usually apart, but which when brought
together pass a current from the circuit of the instrument through the coils of the
impulse magnets. In order to bring them together when an impulse is required
one of the springs has mounted on it a pivotted finger which is kept in a central
position either by a light spring or by magnetic attraction, but which is free to vibrate
to either side. Towards this finger is presented an arm fixed on the oscillating axis
this arm terminating in a V shaped point with an inclined noth on each side of it.

page_text: While this arm oscillates over a considerable range, it in passing the finger merely
causes it to vibrate each way, but when the excursion of the arm is to a certain
extent lessened, the finger instead of being freely passed by the armi is caught in
one or other of the notches, so that when the arm makes its return movement the
spring to which the finger is pivotted is pressed so as to make contact with the
other spring. A current is thus sent through the coils of the impulse magnets at
the inoment when their armature bar is approaching their poles in either direction,
and the attraction acting on the armature gives the required impulse. There may
be two armature bars arranged to be acted on in this manner. In order to adjust
the instrument to a particular electrical force, the armature bars may be made to
slide along the axis or to be inclined more or less out of the magnetic fields, or
while they remain stationary the magnets may be slid more or less away from the
planes of the bars. It is often convenient to transmit through the coils of the
instrument some known fraction of the total current and not the whole of it. For
this purpose I arrange several shunts for the by pass of more or less of the main
current, providing them with suitable contact keys which at the same time operate
to introduce suitably proportioned resistances in the impulse circuit of the
instrument.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Vernon Boys in the Great Seal Patent Office on the
17th January 1883.
CHARLES VERNON BOYS of Wing near Oakham in the County of Rutland
"IMPROVEMENTS IN ELECTRIC METERS "
In the Specifications of Patents granted to me on the 13th October 1881
N° 4472 and on the 2nd February 1882 N° 513 I described forms of apparatus for
measuring the electricity passed through a conductor by counting the oscillations
of a balance governed by an electro-magnet having its coil in the circuit of the
conductor. My present invention relates to an improved construction of apparatus
of this kind, the object which I have in view being to render it more simple and
more readily adjustable to various conditions as well as to render it more regular
and efficient in its action. For this purpose, I fix on a spindle an iron bar rounded
at the ends, this bar being free to oscillate between two limbs of an electro-magnet,
these limbs being circularly hollowed in the middle or having circularly hollowed
pole pieces attached to their middle. The two limbs have on them on each side of
their middles coils of insulated wire which are in the circuit, and they are connected
by iron at their ends, so that their middles close to which the bar oscillates are two
opposite magnetic polar fields. On the same spindle I fix another magnetic bar
which presents its ends towards the poles of a pair of electro-inagnets. These have
their coils occasionally brought into circuit for the purpose of giving an impulse to
the oscillating armature by the following arrangement. A pair of springs are
provided with contact points which are usually apart, but which when brought
together pass a current from the circuit of the instrument through the coils of the
impulse magnets. In order to bring them together when an impulse is required,
one of the springs has mounted on it a pivotted finger which is kept in a central
position either by a light spring or by magnetic attraction, but which is free to
vibrate to either side. Towards this finger is presented an arm fixed on the
oscillating axis, this arm terminating in a V shaped point with an inclined
notch on each side of it. While this arm oscillates over a considerable range, it in
passing the finger merely causes it to vibrate each way, but when the excursion of
the arm is to a certain extent lessened, the finger instead of being freely passed by
the arm is caught in one or other of the notches, so that when the arm makes its
return movement the spring to which the finger is pivotted is pressed so as to
make contact with the other spring. A current is thus sent through the coils of the
impulse magnets at the moment when their armature bar is approaching their poles
in either direction, and the attraction acting on the armature gives the required
impulse. There may be two armature bars arranged to be acted on in this manner.
In order to adjust the instrument to a particular electrical force, the armature bars
may be made to slide along the axis or to be inclined more or less out of the
magnetic fields, or while they remain stationary the magnets may be slid more or
ess away from the planes of the bars. It is often convenient to transmit through
the coils of the instrument some known fraction of the total current and not the
whole of it. For this purpose, I arrange several shunts for the by-pass of more or
ess of the main current, providing them with suitable contact keys which at the
ame time operate to introduce suitably proportioned resistances in the impulse
ircuit of the instrument.
Fig. 1 of the accompanying drawings is a longitudinal and Fig. 2 is a transverse
ection of an electric meter according to this invention, Fig. is a sectional plan
aken on the line X X of Fig. 2, the upper half of the plan being taken at a higher

page_text: level than the lower half, Fig 4 is a side view of the contact springs for the
impulse magnet and Fig. 5 is a plan shewing the arrangement for making contact
to excite the impulse magnet. The fixed framing of the meter consists of two end
frames A A' connecting a base plate B with a top plate B₁. On the sides of the
end frames are fixed the two pairs of iron bars constituting the cores of the two
electro-magnets, the upper pair C C connected at the ends by the iron plates c c¹
being those of the meter magnet and the lower pair D D¹ connected by the
plates d d being those of the impulse magnet. E is the vertical axis pivotted in
the plates B and B' and having fixed on it the two armatures, namely the
armature F for the meter magnet, and G for the impulse magnet, also a pair of
arms carrying weights H H. Both the armatures F and G, are rounded at the
ends, the middles of the magnet bars C C are hollowed at c² and the middles of
the magnet bars D D¹ have hollowed pole pieces d³ projecting towards the
armature G. The bars C C and D D' and also the armatures F and G may be
divided longitudinally or made up of plates. The middle parts of the magnet bars
form the magnetic fields acting on the armatures F and G to maintain their
oscillation, that is to say the upper magnet C C₁ having its coils always connected
in the circuit usually acts alone, but the lower magnet D D¹ acts only when an
impulse is required, in which case its coils are temporarily connected in the circuit
in the following manner. On the axis E is fixed an arm K terminating in a
V shaped point with an inclined notch on each side of it. A finger L is mounted
on M one of two contact springs M and N and is kept by a light spring in a middle
position pointing towards the axis E and within the range of the arm K.
As long
as the oscillation of the arm K is sufficient, the finger L is permitted by the yielding
of its spring to oscillate as far as the arm K can drive it without moving the
spring M on which it is mounted; but if the excursion of the arm K is, so far
reduced that the point of the finger L does not escape one or other of the notches
of K when K moves to the one hand, then on the return stroke of K toward the
other hand, the point of L being caught in the notch is carried with K and in
approaching its central position it pushes back the spring M causing it to make
contact with N, whereby a current is transmitted through the coils of the impulse
magnets D D'. As at this moment the armature G is approaching the pole pieces
of the magnet D D₁ it receives an impulse tending to increase the oscillation of
the axis E, and as the finger L in passing its middle position becomes released
from K breaking the contact of the springs M N, just as the armature G attains its
middle position, at that moment the attraction on G ceases. In order to avoid the
destructive action of sparking at the contacts of M and N, I keep these springs
always connected through a suitable resistance which always allows a feeble
current to pass through the coils of D D. As, owing to this, the armature G is
always subject to a little attraction as it passes the pole pieces of D D', I prevent
this from influencing the action of the magnet C C on the armature F by
hollowing the middles of C C¹n little more than they would be hollowed if the
curve of the hollow were concentric with the rounded ends of F, so that when F
is passing its middle position the force acting on it is somewhat lessened. Iron
screws at c may be used for more delicate adjustment. As it is possible that when
the instrument is cut out of circuit the armature might stop in a middle position,
and therefore could not start of itself when the magnet coils are again put in
circuit, I provide against this by the following arrangement. On the side of the
armature F, 1 fix a V ended stud P and instead of making the end piece ca
fixture I pivot it near its upper edge and fix to it an arm carrying a weight q
adjustable in position or a suitable spring. When the instrument is cut out of
circuit, the end piece c is no longer attracted to the bars C C¹, consequently the
arm Q is permitted to descend and its end dropping at the one or the other side of
the stud P, pushes it to the one hand or the other, thus causing the armature F to
take a position out of centre. When again the instrument is put in circuit, the
end piece c is at once attracted raising the arm Q and so releasing the stud P, and
the armature F being then on the one or the other side of its central position,

page_text: receives an attractive impulse from the magnet C C¹ starting it into oscillation.
For the purpose of registering the number of oscillations which is a measure of the
current passed through the coils of the instrument, I fix on the upper part of the
axis E a boss R having cut in it a cam groove into which enters a pin on an arı 8
of a rocking spindle S. Another arm T on this spindle carries a spring pawl t
which engages with a ratchet wheel geared to a counter. As the axis E oscillates,
the cam groove in R causes the spindle S to rock, thereby, through the pawl and
ratchet, working the counter. The cam groove in R is made with a rather abrupt
slope in its middle, with a straight part to either hand, so that it is only the
middle part of the stroke of the axis that works the counter, there being freedom
for the axis to oscillate more or less beyond the middle of its stroke in either
direction.
Having thus described the nature of my invention and in what manner the same
is to be performed, I hereby declare that I make no general claim to measuring
the current in an electric circuit by registering the number of oscillations of a
vibrating armature subject to the attraction of an electro-magnet having its coil in
the circuit, but I claim:-
First. The construction and arrangement of electric meter, substantially as
herein described with reference to the accompanying Drawings.
Second. In an Electric Meter, the use in combination with vibrating armatures,
of electro-magnets consisting of iron bars having coils on each side of their middles,
so that their middles are rendered polar fields acting on the vibrating armatures,
substantially as described.
Third. In combination with the impulse electro-magnet of an electric meter, the
contact apparatus consisting of the notched arm K, the spring finger L and the
contact springs M and N, arranged for symmetrical action, substar ially as herein
described.
In Witness, whereof I the said Charles Vernon Boys have hereunto set
my hand and seal this Seventeenth day of January in the year of our
Lord One thousand eight hundred and eighty-three.