Improvements in Controlling Devices for Electric Currents.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Controlling Devices for Electric Currents.
I, HERMANN CUÉNOD, of 12, Rue Diday, Geneva, in the Republic of Switzer-
land, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to a controller which is intended to maintain in a
constant condition an electric current produced by a dynamo-electric machine
or other apparatus producing electric energy.
The device is mainly composed of two distinct portions, which are on one side
an electromagnetic regulating device (for instance a voltmeter or an ampere-
meter) of very reduced stroke, and on the other side a click-mechanism, intended
to act upon the regulating mechanism of the motor, (for instance on the admis-
sion or expansion-valve of a steam-engine, on the distributor of a water-wheel
or upon the carrier of the brushes of the dynamo-machine).
The electromagnetic regulating device is composed of an inductor with closed
circuit having a ring-shaped groove in which is placed a coil, the body of which
is preferably made of copper or aluminium. This coil, in which passes a
derivation of the current which is to be regulated, is secured to the end of a
double lever.
The end of the lever carries a piece of metal which is secured to a flexible blade
fixed to the said lever.
The electromagnetic regulating device is provided with a regulating spring
fixed with one of its ends to the said movable lever and with its other end to a
fixed point. A screw and a screw-nut allows the said spring to be more or less
stretched with a view of varying the normal position of the apparatus.
second spring is secured to the lever, the other end of which supports the piston
rod of an oil or air pump (cataract).
A
There is further provided a toothed wheel, which is-keyed on a shaft sup-
ported in a fixed bearing; the said wheel may be rotated in opposite directions,
by means of clicks normally kept raised by means of two bell-crank-levers each
provided with a tappet. The said clicks and their bell-crank or stop-levers are
mounted upon a rocking support rotatively mounted on a sleeve concentric to
the before mentioned shaft, the said support being rocked to and fro by means
of a mechanism composed of a crank shaft acted upon by any suitable motor,
and connected to the lower arm of the support by means of a rod or link. The
stroke of the support is calculated so as to cause one of the clicks to rotate the
toothed wheel forward one of its teeth at every revolution of the crank. There-
fore if one of the bell-crank-levers is raised the corresponding click will be put
into engagement with the wheel, and it will cause the same to be rotated one
of its teeth at every rocking-motion of the support. This is accomplished by
means of the double lever and a stopper carried thereby, which when the current
has its normal value, does not meet either of the tappets, but meets with either
of the tappets as soon as the current varies, causing the lever to be oscillated
in one sense or the other; the stopper then causes the corresponding bell-crank-

page_text: lever to be disengaged from the corresponding click and the wheel is then acted
upon by the click. Fillings or stops are placed on the circumference of the
toothed wheel and are intended to temporarily raise the clicks, or better rollers
fixed to these latter, when the toothed wheel has brought the controlling
mechanism to either of its extreme positions.
By displacing the said fillings on the circumference of the toothed wheel,
the limit of control of the apparatus may be varied at will.
To allow the clicks to again assume their position of rest, without any risk
of having the same touching the toothed wheel; a fixed stud is arranged on the
frame and is intended to raise at each swinging motion of the rocking lever
the clicks pivoted to this latter, and to allow the crank-levers to meet the clicks.
When one of the said crank-levers is raised, it remains long enough in its raised
position to prevent its again catching the corresponding click before the same
has left the stud.
The device above described would work well if the controlling motion of the
apparatus were instantaneous, as is the case when the device is used in con-
nection with a storage battery, or to control a current with more or less self-
induction. But in cases where the controlling motion is retarding with regard
to the working of the apparatus, it is necessary to provide subduing means to
make it possible to rapidly control without allowing the formation of periods.
For this purpose there is provided a lever pivoted to a fixed point and pro-
vided with a toothed segment engaging with a toothed pinion journalled on the
toothed wheel or on its shaft. At a suitable distance from the fulcrum of the
said lever there is secured the cylinder of an oil or air pump. As soon as the
controlling motion is performed the pump is raised or lowered; the spring to
which the piston is suspended, is stretched and it tends to bring back the lever
into its original position. If the fault which is to be corrected is a large one,
the controller acts until the said spring is sufficiently stretched as to allow the
lever to be brought back into its normal position.
Little by little the pump recedes and the spring gradually resumes its first
or normal condition to the weight of the piston and its rod.
Little by little the regulator moves on, slower and slower to the final position
corresponding to the perfect correction of the fault.
The oil or air pump only serves to bring the spring back to the same degree
of tension. There will be a permanent percentage which may be chosen as small
as wanted, in making the spring of a power corresponding to the said percentage.
The arm of a regulating mechanism may be fixed to the shaft of the toothed
wheel.
The electromagnetic regulating device is composed of an inductor intended
to produce in a single air-gap an intense uniform annular field.
A coil in which passes the current and which is connected to the annular
field tends to displace itself in the direction of its axis with an energy depending
upon the length of the wire, the intensity of current and the magnetic field.
This field is created by the current which is to be regulated, the total or partial
intensity of which, travels in an exciting coil, surrounding a central core.
iron sleeve encloses the magnetic circuit, with the exception of a ring-shaped
groove in which the coil is introduced. Thus the variations are very sensitive,
on account of the strain which is growing approximately like the medium of the
current.
An
The movable coil is very light and its framing is made of conducting material
(copper or aluminium) in order to act like a brake because of the currents which
are produced by the slightest motion and render the apparatus periodical.
It is obvious that the controller above described may be provided with steel
inductors and permanent magnets.
For alternating currents, the same construction may be used. But in this
case the magnetic circuit must be sufficiently subdivided in order to prevent
the Foucault's currents interfering with the proper working of the apparatus.

page_text: soon as the controlling motion is performed, this pump is raised or lowered;
the spring S to which the pinion .P is suspended, is extended, and tends to bring
back the lever into its original position. If the fault which is to be corrected
is a large one, the controller acts until the said spring S is sufficiently extended
as to allow the lever to be brought back into its normal position.
Little by little the pump recedes, and the spring S gradually resumes its
first or (normal) condition to the weight of the piston and its rod.
Little by little the regulater moves on, slower and slower to the final position
corresponding to the perfect correction of the fault.
The oil or air pump only serves to bring the spring S back to the same degree
of tension. There will be a permanent percentage which may be arranged as
small as required by constructing the spring S of a power corresponding to the
said percentage.
In the section of the mechanism shown in Figure 2 the arm Q of a regulating
mechanism is shown which is fixed to the shaft of the toothed wheel D.
The electromagnetic regulating device is composed of an inductor adapted
to produce in a single air-gap an intense uniform annular field.
A coil in which passes the current, and which is connected to the annular
field, tends to displace itself in the direction of its axis with an energy depending
upon the length of the wire, the intensity of current, and the magnetic field.
This field is created by the current which is to be regulated, the total or partial
intensity of which travels in an exciting coil m, surrounding a central core M.
An iron sleeve N encloses the magnetic circuit, with the exception of the ring-
shaped groove in which the coil is introduced.
The movable coil is very light, and its framing is made of suitable conducting
material, such as copper or aluminium, in order to act in the manner of a brake,
owing to the currents which are produced by the slightest motion, and thus
render the apparatus periodical.
It is obvious that the controller above described may be provided with steel
inductors and permanent magnets.
For alternating currents, the same construction may be used. But in this
case the magnetic circuit must be sufficiently subdivided in order to prevent
the Foucault's currents interfering with the proper working of the apparatus.
The lever being perfectly movable, and its moving angle very slight, various
arrangements may be used to cause said lever to be acted upon by the current.
The operation of the above described apparatus is as follows:
When a current of normal intensity passes in the derivation forming the
coil n at the same time as in the exciting coil m, a repulsion is produced between
the two coils m and n which causes the stop b carried by the lever to be placed
into a predetermined normal position owing to the tension of the spring c, and
in the said normal position the swinging motion of the support B causes neither
of the tappets to engage with the stop b.
If the intensity of current increases in the coils, the arm of the lever / which
carries the coil n is raised, through the increasing repulsion, which produces
the lowering of stop b, so that the tappet 2 meets with the stop b, and acts
upon its click R³ which causes the rotation of the toothed wheel D in the direc-
tion of the arrow 2 at each swinging motion of the support B the click R² is
raised again by the fixed stud a on the frame, and locked to its bell-crank-
lever, but as long as the stop 6 meets the tappet the click R2 always falls
back on the toothed wheel D and causes it to rotate in the direction of the
arrow 2, the wheel being prevented by friction, from accidentally turning back
again.
If on the contrary the intensity of the current is diminishing, one end of the
lever falls down, and the stop b is raised, so that instead of the tappet 2, it
is the tappet which is in line with the stop b, so as to cause the toothed wheel D
to be rotated by means of the other click R' in the direction shewn by arrow 7.
In its rotation in the direction of the arrow 1 the toothed wheel D carries the

page_text: lever E to its lowest position, which causes the spring S to be extended, thus
tending to bring the lever f back to its normal position.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. An automatic controlling device for electric currents characterised by the
combination of an electromagnetic regulating device having a very small stroke,
with a lever bearing a stop b adapted to be displaced within the path. of the
tappets and 2 of bell-crank-levers r¹ and carried by a rocking-lever B con-
centrically pivoted to the axis A, with clicks R¹ and R2 adapted to cause the
wheel D to be rotated when the clicks are disengaged from the bell-crank-
levers or 2, substantially as herein before described and illustrated in the
accompanying drawings.
2. In an automatic controlling device, as specified in Claim 1, a spring S
connecting lever E with the lever 1, by means of a pump, substantially as herein-
before described and illustrated by the accompanying drawings.
3. In an automatic controlling device, as specified in Claim 1, an electro-
magnetic regulating device composed of a core M surrounded by a coil m of a
tube N and of a hollow coil n supported by lever with spring c, substantially
as herein before described and illustrated in the accompanying drawings.
Dated this 19th day of March 1900.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.