IM- PROVEMENTS IN PHONIC WHEELS, OR IN DRIVING AND REGULATING THE SPEED OF WHEELS BY ELECTRICITY
Year: 1878

page_text: LETTERS PATENT to Poul la Cour, of Copenhagen, for the Invention of "IM-
PROVEMENTS IN PHONIC WHEELS, OR IN DRIVING AND REGULATING THE SPEED
OF WHEELS BY ELECTRICITY."
Scaled the 12th November 1878, and dated the 17th May 1878.
PROVISIONAL SPECIFICATION left by the said Poul la Cour at the Office
of the Commissioners of Patents on the 17th May 1878.
POUL LA COUR, of Copenhagen. "IMPROVEMENTS IN PHONIC WHEELS, OR IN
DRIVING AND REGULATING THE SPEED OF WHEELS BY ELECTRICITY."
This Invention consists in making a wheel, technically called a phonic wheel,
move with a rapidity dependent only upon the rapidity of oscillation of a phono-
electric current, serving as well for a motor as a regulator of the wheel.
It will be the most convenient to explain what is meant by a phono-electric
current.
If a rapidly intermitting and electric conveying bridge be produced in one way
or another, either by allowing a tuning fork or any other oscillating body to make
contact by connection, or by allowing a rotating body to perform rapidly successive
connections, or another body and an electric current is conducted through the
intermitting bridge, the current will likewise be intermitting because the current
at times, when the bridge is broken, has the force of zero, and at times, when
the bridge is closed, has a constant force, which is graphically represented in
Figure 1.
If a resistance of induction be found on a spot in the circuit of the current, or if
to prevent the electric spark in the intermitting bridge the two sides of the bridge
be united by a shunt, or if by any way whatever the variations of the current are

page_text: made not suddenly, the current cannot well be called intermitting. It is therefore
that I comprise within the more common denomination of phono-electric current
those electric currents of 'which the force is a periodical function of time, conse-
quently, such currents are graphically represented in Figures 1 and 2.
Figure 3 is a top view, and Figure 4 a section of the phonic wheel. It consists
chiefly in a toothed wheel of iron R, R, which can turn round its axle in such a
manner that the teeth of it pass very near the pole of an electro-magnet m without
touching it. If now a phono-electric current is going to be conducted through the
electro-magnet, that is to say, from the screw H to the screw R, the wheel R, R,
when in repose will not only be in equilibrium because of a certain tooth, which
chances to be nearest the pole, being attracted by the latter, but the wheel will be
in a continuous equilibrium, equilibrium of motion, when such a rapidity has been
first given to it that a tooth passes near the pole for each wave of the phono-
electric current running through the electro-magnet, which will be understood by
what follows.
=
In Figures 5, 6, 7, is represented the axle of the wheel; m, the middle line of the
pole; and s, t, the way which the middle line of the tooth passes within the time
of the wave s running through the electro-magnet. On the way 8, m, the rapidity
of the wheel before the tooth has reached the electro-magnet will of course be
accelerated by the attraction, and on the way m, t, the wheel, after the tooth
having passed the pole, will be retarded by the same. Provided the wheel moves
thus (Figure 5), that the acceleration and the retardation are equally great
(8mm t), the rapidity of the wheel will undergo no alteration on account of the
attractions, so that the wheel is in equilibrium. But it may easily be understood
that the equipoise is steady, that is to say, that if any exterior reason produces a
little change in the movement the wheel itself will strive to resume it exactly.
Provided then that an exterior cause will keep the wheel back (Figure 6), the
acceleration will evidently become greater than the retardation (s m> mt), so that
the attractions will strive to do away with the effect of deviation. On the other hand,
if an exterior cause will advance the wheel too much (Figure 7) the acceleration
becomes less than the retardation (s m < m t), so that the attractions, even in
this case, will strive to do away with the effect of deviation. The wheel goes on
keeping itself in its course, fixed by the phono-electric current in such a manner
that one tooth passes the pole for each wave running through the electro-magnet.
If exterior forces are allowed to operate upon the wheel in the one or other
direction, the wheel can overcome these, and unaltered maintain its course. Con-
siderations, such as the above mentioned, show that the wheel may be in a steady
equilibrium, by certain other velocities, such, namely, as are multiple or sub-
multiple of the above mentioned, but the wheel is maintained with the strongest
force in the first-mentioned velocity.
The phono-electric whoel can of course not put itself into motion, which is done
by turning it by the help of the button d (Figures 3 and 4).
As it would be rather difficult for the inexperienced to hit upon the right velocity,
a remedy is applied which renders it easy to give to the wheel the right velocity.
This remedy consists in a capsule, including a liquor of great specific gravity; for
instance, a wooden cylinder capsule b, b, (Figure 4) applied concentrically on the
axle of the wheel, in which is found a ring-formed space g, g, (Figure 4) filled with
quicksilver. The quicksilver having partly a motion of its own independent of the
wheel, it acts upon the wheel on account of its friction against the sides of the
capsule. The result attained by this reinedy is that the wheel, if from the first a
too great velocity has been given to it, so great and of so long a duration that the
quicksilver on account of the friction has also got a greater rapidity than that by
which the wheel will be put into equilibrium, will after having been slackened so
much as to be reduced to this velocity go on maintaining it.
The quicksilver renders also in other regards the revoltions of the wheel more to
be relied on.

page_text: The exterior form of the apparatus may in different ways undergo changes
without changing its very nature, as it has been shown in the above description.
The electro-magnet m (Figures 3 and 4) may be shaped in the form of a horse-
shoe, and applied in such a manner that two different teeth at the same time pass
the two poles.
Instead of the toothed wheel of iron a wheel of brass may be applied, in the
circuit of which in the place of the teeth anchors of iron or steel magnets are fixed,
which are acted upon by the electro-magnet m.
Any other not essential alteration may likewise be made.
A phono-electric current produced by a tuning fork, or any other oscillating body,
being very steady, the phonic wheel kept going by such a current affords a very
steady movement. If on the other hand, the phono-electric current be produced by
the movement of such a body as a toothed wheel or the like in such a manner that
the rapidity of oscillation of the current may change from time to time, the phonic
wheel will move exactly, thus that a tooth passes the pole for each wave running
through the electro-magnet, so that the wheel be enabled to keep a course
completely synchronal to the movement of the body which has produced the phono-
electric current.
On account of the qualities of a phonic wheel we use it for chronographs,
synchronal watches, different kinds of telgraphing imitations, enumerations of rapid
movements, and the like.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Poul In Cour in the Great Seal Patent Office on the 15th November
1878.
POUL LA COUR, of Copenhagen. "IMPROVEMENTS IN PHONIC WHEELS, OR IN
DRIVING AND REGULATING THE SPEED OF WHEELS BY ELECTRICITY."
This Invention relates to isochronous and synchronous movements operated by
electricity, by the aid of which mechanical movements, such as common clocks,
chronographs, printing, or recording, or multiplex telegrapha, phonographs, etc., inny
be regulated and controlled so as to have an absolutely isochronous or synchronous
motion, which motion may be regulated so as to affect simultaneously all the move-
ments or machines within the electrical circuit by a simple adjustment of the
regulator or regulating movement, and it consists,-
First. In the construction, combination of parts, and arrangement of a magnetized
reed or tuning fork, which is kept in vibration by the action of two electro-magnets,
one on each side of its magnetic poles.
And, Second. In the construction, combination of parts, and arrangement of a
toothed wheel and electro-magnet, the intermittent current or pulsations of which
are regulated by the device which forms the first part of my Invention, and
any given number of which (each forming a part of the movement to be brought
into synchronous action with the initial or principal isochronograph) may be
operated synchronously or in perfect unison by a single regulator, constructed in
accordance with what forms the first part of my Invention, and which I shall now
proceed to describe more fully.
On the two Sheets of Drawings hereto annexed Figure 1 is a side elevation of
my improved isochronous and synchronous electrical movements; Figure 2 is a top
plan of the same.
Figure 3 is a top plan of the regulator, which forms the second part of my Inven-
tion, and is used in combination with the first part thereof, or that part illustrated
in the preceding two Figures; Figure 4 is a vertical section of the line a', ',
Figure 3.
Figures 5, 6, and 7 are diagrams, illustrating the operation of the regulator shown
in Figures 3 and 4.
Similar letters of reference indicate corresponding parts in all the Figures.
Reference being had to Figures 1 and 2, A. denotes the base plate, upon one end
of which is secured an isolated metal block K, provided with the binding screw K³,
and perforated longitudinally so as to form a socket for the insertion of the reed or
tuning fork n, p, 8, which is made of steel and magnetized in like manner as an
ordinary horse-shoe magnet, its magnetic poles n and s projecting horizontally
between the poles S and N of the electro-magnets M, M. One end of the wire coil
of these electro-magnets (denoted by K) is connected to the base plate A while the
other end is connected with the isolated binding screw L. Upon the base plato A
is pivoted upon a projecting stud or pin x a lever arm u, v, which may be adjusted
by means of a set screw V, the end or point of which works against the long arm v,
while the short arm u impinges upon a spring secured upon the base plate. This
short arm u is provided with a vertical, or nearly vertical, platina contact spring c,
which by manipulating the set screw V can be brought into direct contact with the
pole n of the tuning fork, which has on the side which comes in contact a thin
plate of platina attached through which the contact is established.
It follows that when one of the poles of an electrical battery is connected with
K', K, and the other with I, a vibrating motion will be imparted to the tuning
fork n, p, 8, because the current will pass from K through the branch n of the
tuning fork to the contact c, and consequently through the base plate A to the
electro-magnets M, M, and through them to the binding screw L, which closes
the circuit and magnetizes the poles of the electro-magnets. These will attract the

page_text: poles n, s, of the tuning fork which become expanded, thereby breaking the contact
between n and c, and consequently breaking the circuit. This stops the current
through the coils, wound around the electro-magnets which now lose their attrac-
tion, and the branches n, s, of the tuning fork will return to their normal position,
touching the contact c which re-establishes the circuit, and so on. In this manner
an intermittent current is produced by the vibration of the branches of the tuning
fork, the intervals or pulsations of which are regulated by the tune or key of the
fork n, p, 8. This tune or key may be regulated and changed at will by sliding
adjustable weights Y, Z, one upon each of the branches n, s, which may be secured
in any given position by set screws.
The mechanism and combination of parts, herein-before described, would be
sufficient to produce an intermittent current which might be utilized for the purpose
of imparting motion to the phonic wheol, but still better results are produced by
establishing an intermittent contact between the other pole s of the reed or tuning
fork and a contact spring c', secured upon one end of a horizontal lever arm u³, v³,
which is pivotted upon an isolated stud or pin x¹ projecting from the base plate,
and may be manipulated in like manner as lever arm u, v, by a set screw V and
tension spring, an isolated wire connects the isolated contact c¹ with an isolated
binding screw H, and it follows that when the tuning fork is caused to vibrate in
the manner described an intermittent bridge is established between H and K, which
is made use of in the second part of my Invention which I shall now proceed to
describe, reference being had to Figures 3, 4, 5, 6, and 7 of the Drawings.
When
This apparatus consists essentially of a base plate A', an electro-magnet m, and
a horizontally pivotted toothed wheel R, made of iron, the teeth of which as it
rotates will pass in close proximity to the pole n' of the electro-magnet m, yet
without touching this. From a battery indicated by B the circuit passes through
the intermittent bridge formed between H and K and the electro-magnet m, as
represented in Figure 3, thus producing an intermittent current through the latter,
which will be in exact unison with the vibrations of the tuning n, p, 8.
the wheel R is at rest then that one of its teeth which happens to be nearest to tho
pole m of the electro-magnet will be retained or caused to remain fixed in that
position on account of the magnetic attraction of the pole, but if the wheel is set
in motion with such a velocity that a tooth shall pass pole n for each impulse of
the intermittent electrical current, then this velocity will be regulated and con-
trolled by the action of the electro-magnet m, which receives its impulses from the
tuning fork in the manner already described.
This action of the electro-magnet in reference to the rotating wheel R will bo
more clearly understood by reference to the diagrams represented in Figures 5, 6,
and 7 of the Drawings. Suppose that the dash and letter m indicates the central
or axial line of the pole m of the electro-magnet, and the letter r indicates the centre
of wheel R, which is supposed to rotate in direction indicated by the arrow.
Now if the central line of one of the teeth is moved during one impulse from the
points to t, it (the tooth) will be accelerated on its way from 8 to m, but retarded
on its way from m to t. If, as in Figure 5, this acceleration and retardation are
equal, the velocity of the wheel will not be affected by the electro-magnet, but if
the wheel should commence to lose or go slow, Figuro 6, the acceleration 8, m, will
increase and the retardation m, t, decrease; consequently the pole of the electro-
magnet will increase the velocity of the wheel, and the attraction by which this is
accomplished will increase in the same ratio as the wheel slows or loses time. On
the other hand, if the wheel gains or increases in speed, Figure 7, the acceleration
8, m, will be decreased, while the retardation m, t, will increase, so that in this case
the electro-magnet will have exactly the opposite effect, and retard the velocity of
the wheel, which retardation will increase in the same proportion as the velocity of
the wheel would otherwise increase.
From the foregoing it will be observed that this simple apparatus may be used
both as a motor and as a regulator, and in either capacity it will not be affected by
outside influences, whether these operate in the same direction as or contrary to the

page_text: rotation of the wheel. It must be understood, of course, that these outside causes
or influences should not exceed a certain limit. If, for instance they should cause
the wheel to lose or increase during a single impulse a distance equal to about one-
half the space between its teeth, it may happen that the balance of motion will be
broken, and the wheel will come to a stand still; but unless exterior causes should
be sufficient to produce divergence to about that extent, they will exert no influence
upon the movement of the wheel, which will rotate in unison with the pulsations of
or impulses in the electro-magnet.
If preferred, the wheel R may be made of wood, hard rubber, ivory, or brass, and
its teeth substituted by armatures made of iron or magnetized steel fastened on the
circuit of the wheel parallel with the axis.
Instead of the single electro-magnet m, a horse-shoe magnet can be applied.
In either case it would require some skill and experience to start it at the proper
speed, so as to bring it under the controlling influence of the electro-magnet; but
this difficulty may be overcome by attaching to the under side of the disc or
wheel R, a cylindrical case S, Figure 4, filled with mercury and carefully sealed.
On account of the inertness of the mercury this will by its friction against the inner
annular wall of the cylindrical reservoir S gradually and very evenly reduce the
variations of the velocity of the wheel, which will thus by almost imperceptiblo
degrees attain the true grade of velocity or movement, in which it will then remain
by the action of the electro-magnet in the manner described.
This regularity of motion having been once attained, it is obvious that the wheel
R may be employed for the purpose of moving and regulating clocks, chronographs,
printing telegraphs placed at a distance from each other, or other mechanisms where
a synchronous motion is desired, one wheel R with its corresponding electro-magnet
being used in cach apparatus, and all of these brought within the circuit of the
intermittent bridge H, K, as described; or, in other words, a single tone giver,
reed, tuning fork, vibrating plate, or chord, can be used to move several tone
wheels, so that several mechanisms will be in synchronous action with each other,
and each isochronic in itself, regardless of the distance that may intervene between
them.
Besides the method described there are various other ways by which the same
result may be effected. For example, the first wheel R, through which the regu-
lating intermittent current passes, may be used to communicate the electrical
pulsations to successive wheels or regulators by constructing its vertical pivot or
axle with a sliding contact, which as the wheel revolves will touch successive
stationary contacts arranged in circular form around but isolated from the wheel.
The breaks in the circuits thus produced may be employed to establish or form
another intermittent bridge, which will be of the same key as the first one, and so
on; or the intermittent current may be sent direct from the apparatus which forms
the first part of my Invention to and around the electro-magnets of a similar appa-
ratus located at a distant station, which will cause the reed or tuning fork of the
latter to vibrate in the same key or in exact unison with the tuning fork at the
initial station. Even if the key of the two tuning forks should in themselves and
after adjustment differ somewhat, the impulses of the current received from the
initial station will regulate the vibrations, and thereby set the key at the receiving
station; and I have found by experiment that even if purposely or accidentally the
intermittent current from the initial station is deprived of some of its impulses or
pulsations so as to leave spaces, this will not affect the key at the receiving station,
so that the synchronic movement at both stations will remain uninterrupted and
intact, a circumstance which may be made available in various electrical and
telegraphic mechanisms in which it is desirable to obtain synchronous movements
or impulses.
In order to prevent the burning and destruction of the platina contacts described
in the first part of my Invention, the contacts or conductors on each side of the
intermittent bridges-may be connected each by an isolated wire, with resistance coils
suitably arranged in the base plate of the apparatus.

page_text: Having thus described my Invention, I would have it understood that what I
claim and desire to secure by Letters Patent is,―
First. Apparatus in which a permanently oscillating tuning fork or other tone
giver produces an intermittent or undulating electric current used for conserving
and regulating the motion of a wheel.
Second. The combination of an intermittent bridge H, K, Figure 3, a battery B,
and an electro-magnet m, whereby is produced intermittent attractions or repulsions
between the electro-magnet and a tooth wheel R, or a cylinder provided with anchors,
as described.
Third. Apparatus in which a tooth wheel or a cylinder with anchors are in mobile
and stable balance, because intermittent attractions or repulsions abrogate the effect
of exterior forces that possibly would decrease or increase the velocity of the wheel,
Figures 5, 6, and 7, as described.
Fourth. The motor or regulator wheel R pivotted horizontally in a base plate a',
and provided with a concentric cylindrical chainber S containing mercury or similar
inert fluid, substantially as and for the purpose herein-before set forth.
In witness whereof, I, the said Poul la Cour, have hereunto set my hand and
seal, this Seventh day of November, in the year of our Lord One thousand
eight hundred and seventy-eight.
DATTI
COTID