CERTAIN IMPROVEMENTS IN APPARATUS FOR RE- GULATING THE SPEED OF STEAM, AIB, OR WATER ENGINES
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JEAN
BAPTISTE FRANÇOIS JOUANNIN, of Upper Ebury Street, Pimlico, in the County
of Middlesex, Mechanic, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Ninth day of July, in the sixth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Jean
Baptiste François Jouannin, Her especial license, full power, sole privilege
and authority, that I, the said Jean Baptiste François Jouannin, my
executors, administrators, and assigns, and such others as I, the said Jean
Baptiste François Jouannin, my executors, administrators, or assigns, should
at any time agree with, and no others, from time to time and at all times
during the term of years therein mentioned, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, an Invention of "CERTAIN IMPROVEMENTS IN APPARATUS FOR RE-
GULATING THE SPEED OF STEAM, AIB, OR WATER ENGINES," being a communication
from a Foreigner residing abroad; in which said Letters Patent is contained
a proviso obliging me, the said Jean Baptiste François Jouannin, by an
instrument in writing under my hand and seal, particularly to describe and
ascertain the nature of my said Invention, and in what manner the same is
to be performed, and to cause the same to be enrolled in Her Majesty's High
Court of Chancery within six calendar months next and immediately after the
date of the said in part recited Letters Patent, as in and by the same, reference
being being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Jean Baptiste François Jouannin, do hereby declare that the nature of the
said Invention, and the manner in which the same is to be performed, are par-
ticularly described and ascertained in and by the following description
thereof, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say) :--
These Improvements in Apparatus for Regulating the Speed of Steam, Air, or
Water Engines, consist of a machine composed of a clock and of a peculiar com-
bination of wheelwork called by the Inventor differential gearing, and which
wheelwork is placed between the clock and the engine that requires regulating.
The precision with which a clock is worked by a weight and pendulum, and
marks the time, is well known, and it is this ingenious instrument that is
made to communicate its own regularity to engines of infinitely greater power.
The Figures in the Drawings hereunto annexed represent the different parts of
the apparatus at full. size for a steam engine of moderate power, but when
engines of considerably greater or less power are employed the dimensions and
proportions of the various parts must of course be changed, as will be readily
understood by any intelligent mechanic; also the number of teeth of the wheels
and pinions and the threads of the screws should be calculated according to
the speed, and, consequently, the power of the engines. The following descrip-
tion and proportions, and the numbers employed, are calculated for a speed of
thirty strokes of the piston per minute, or eighteen hundred per hour. In
describing the construction of the apparatus I shall be obliged to describe
twice over some of the parts, in order to explain more perfectly the arrangement
of the differential wheelwork or gearing, and the manner in which it works, so
that the truly extraordinary effect which it produces may be made perfectly
evident and intelligible. This effect is to oblige a common axle (that is to
say, an axle which carries several wheels, and may be put in motion by two
separate forces, to both of which it is common) to move in one way or the
other with a certain speed when this movement is produced by one power alone,
and with double this speed when the other mover adds its power to that already
in action, provided both powers are acting, the same way; but if, on the con-
trary, these forces should be made to act with equally the same power and
speed, but in opposite directions, the axle would remain stationary; but if the
speed given by the two forces should not be equal, the axle would have such
an amount of motion as would correspond to the difference between the two
speeds. In giving numbers to the wheels of the differential gearing, any
number may be taken, but two of these wheels which gear into each other
must have the same number of teeth and be of the same diameter; and of the

page_text: two others, which also gear into each other; one is half the diameter and has
half the number of teeth of the other. The wheels c, d, Figs. 1 and 2, have
each fifteen teeth, and gear into each other; the wheels a and b an gear into each
other, and the first has twenty teeth and the latter ten teeth; the wheel a is
fixed to the common axle or shaft e, shown by dots in Figs. 1 and 2; the
wheel c is fastened upon one end of a hollow shaft f, which carries at its other
end a worm wheel g, which may be considered as the first mover; the worm
wheel h may be regarded as the second mover, and is also fixed upon a hollow
shaft; a projecting pin or stud i, is fixed to one side of the worm wheel h, and
upon this pin the two wheels b and d, which are fixed to a
mounted, and turn on their axles independently of the pin i. From the above
explanation it will be seen that the axle e passes freely through the two hollow
shafts, of which one carries the wheels c and g, and the other the worm wheel
h. Upon one end of the axle e the large wheel j is fixed.
hollow shaft, are
I will now demonstrate that the effects before mentioned really do take
place, viz, that the common axle will move when one of 'the forces is put in
motion whilst the other remains stationary; that putting in motion the second
force either adds to or counteracts the speed of the first according to the way
in which the second moves. In fact, let us suppose that the first mover or
force, viz., the wheel g, makes one revolution rounds its axis, and that the second
h remains stationary, the wheel c, which is mounted on the same hollow shaft as g,
will also make one revolution, and necessarily will communicate the same amount
of motion to the wheel d, into which it gears, and as the latter is mounted on
the same shaft as the wheel b, that gears into a, which is fixed to the common
axle e, it will consequently cause the axle to make one half of a revolution.
Let us now suppose that the first mover g is stationary, and the second, h, in
motion, this latter would carry round with it the two wheels b and d, which
are connected together, as before mentioned, and will oblige them to make an
orbicular revolution round the two wheels a and c, but at the same they will be
obliged to make one revolution round their own axis, as the wheel d is of the
same diameter as the stationary wheel c, and as the wheel 6 must also revolve
with d, and gears into the wheel a, this latter, for every rotation of the whee.
b, must make half a revolution, and consequently carry round with it the
common axle e, to which it is fixed. We have said that the axle e would have
no motion if the two forces act at the same time in contrary directions, and
with the same speed as would take place in the properly regulated state of the
engine, the speed of which is designed to govern; in this case the axle of
the throttle valve or valve in the stopcock being in communication with the axle
e, it would remain stationery; if, on the contrary, the balance of speed between

page_text: the two forces ceases because the motion communicated to one of them by the
steam engine should be diminished or increased from the fact of the steam not
then being in relative proportion to the resistance, then the axle e would receive
a slight motion, and would act upon the axle of the valve in the steam cock in
order to diminish or increase the supply of steam. All that has been said is in
consequence of the wheels g and h being considered as the moving powers, but
in reality the moving powers are, first, the engine that is to be regulated; and,
secondly, a weight governed by a clock which has its own particular weight.
Fig. 1 represents a side view of a clock, and also the differential movement.
The wheels g, h, and j, are also seen in this Figure. I do not consider it neces-
sary to describe the clock, because it is nothing more than an ordinary one. I
will only observe that it would be as well to have an additional wheels, and
pin t, to wind up the clock, so that a clock face and hands u, u, may be
employed to indicate the hour. The number of teeth given to the wheels is
calculated for the pendulum to make four thousand five hundred beats per
hour. Upon referring to Fig. 1 a pendant lever, with a fork at one end com-
municating with the pendulum, will be seen at k, k. Another lever and fork,
seen in Figures 1, 2, 4, and 5, is fixed upon the end of the axle m, of an addi-
tional escapement n belonging to the differential wheelwork. This latter fork
7 is connected to the pendulum of the clock, and follows all its motions, which,
by means of this escapement are communicated to the differential wheelwork.
I will now, with the assistance of Figures 1, 2, 3, 4, and 5, explain in what
manner the effects of the differential motion are employed to regulate or govern an
engine that makes one thousand eight hundred strokes of the piston per hour, and
in order to do thus it will be necessary to understand perfectly in what manner the
wheels are mounted, and how they are put in motion. Upon referring to Fig. 1, it
will be seen that the common axle e, shewn by dots in this Figure, carries (as
has been already mentioned) the wheels a and j, and the wheels c and g are
also fixed to the hollow shaft f, through which the common axle e passes and
turns freely. It must also be remembered, that the worm wheel h is fastened
on a hollow shaft, which turns freely on the axle e, and that this worm wheel h
carries the two small wheels b and d; and upon referring to Fig. 2 it will be
seen that the worm wheel h gears into an endless screw o mounted on an
upright axle, which carries at its upper end a flyer p, seen also in Figs. 1 and 4;
the worm wheel g also gears into an endless screw q, with two threads. This
screw is actuated by the engine, and performs exactly the same number of
revolutions as the piston does strokes in the cylinder. The wheel g has
twenty-four teeth. and makes one hundred and fifty revolutions per hour in the
direction of the arrow, and as the small wheel c is connected to it, the latter

page_text: must consequently revolve the same number of times, and by gearing into the
wheel d, of the same diameter and number of teeth, it makes the latter also revolve
with it, and the small pinion 6 being mounted on the same hollow shaft as d,
takes the same movement, and as 6 has only ten teeth, and a, into which it
gears, has twenty, the latter, for every complete rotation of the former, will
make one half a revolution in the same direction as c and g. If the worm
wheel h should not move the small wheels d, b, at each vibration of the
pendulum, and thereby destroy the rotation of the wheels c and g, the common
axle e would be obliged to move; therefore, when there is a balance or equality
between the speed of the engine and the pendulum of the clock, there will be
no movement of the common axle e, as the pinion 6, instead of giving motion
to the wheel a, which is fixed to the axle e, will merely travel round it.
The worm wheel h has thirty teeth sufficiently inclined to be able to impel or
actuate the endless screw o, which has two threads and turns in the direction
of the arrow. The shaft on which the screw o and flyer p is mounted, carries
an arm r, which strikes alternately against the right and left hand pallets n, n,
of the escapement mounted on the horizontal shaft m. A rod with a forked
end is connected to one end of the shaft m and descends downwards, and bears
against the pendulum rod of the clock, as seen in Figs. 1 and 5. The rod
by bearing against the pendulum (see Figures 1, 2, 4, and 5,) follows all its
movements, and makes with it four thousand five hundred beats per hour, and
if we multiply thirty (the number of the teeth of the worm wheel h) by one
hundred and fifty, the number of revolutions that this wheel ought to make,
we shall find four thousand five hundred, which can only be obtained by two
thousand two hundred and fifty revolutions of the endless screw o, but as
this screw makes only half a revolution for each vibration of the pendulum,
it is evident that four thousand five hundred beats of the pendulum are
required to make one hundred and fifty revolutions of the wheel h.
Fig. 3 represents a front view of the wheel j, and of the segment rack v, also
seen in plan in Fig. 2. These two work into each other; the number of their
teeth is arbitrary. It is only necessary that the toothed part of the segment
rack v should be so constructed that all the movements of the wheel j should
be transmitted thereto. Upon the centre of motion of the segment rack vis
mounted a lever w, at the end of which, connected by a hinge joint, is an upright
rod or arm x, which carries a ball or weight X, see Fig. 6, and may be of any
convenient length, according to circumstances. This weight is the second mover,
and at the upper end of the rod a is another hinge joint, by which it is connected
to one end of a balance lever y, the other end of this balance lever being in com-
munication with the throttle valve situated on the supply steam pipe. It must now

page_text: be understood that the upright arm or lever a, which carries the ball or weight,
is mounted at the end of the lever w, and that consequently the segment rack
obliges the large wheel j to turn in the direction of the arrow: It is this con-
stant action of the weight upon the wheel j which, by means of the wheel a
gearing into the small pinion 6, obliges the wheel h to revolve in the direction
of the arrow, with a certain 'speed' regulated by the escapement m, n; and to
carry with it the two small wheels brand d. If the wheel 9, actuated by the
engine, turns with a speed of one hundred and fifty revolutions in an hour,
the clock having permitted the worm wheel h also to revolve one hundred and
fifty times, there will be no motion transmitted to the wheels a and j, or the
segment rack v, and consequently the throttle valve will not be acted upon, but
as the power of the steam varies every moment the wheels a, j, and segment
rack v, and the levers connected therewith, will be actuated, and will not allow
more than the proper quantity steam to pass; but if it should happen that
the supply or power of the steam should not be found to be in proportion to
the resistance to be overcome, the lever w and weighted rod would descend
until the last tooth of the segment rack would arrive at the point z, Fig. 3,
and then the clock would stop regulating until there should be enough steam.
In this case the little pins or studs on the side of the wheel g, see Figs: 1
and 2, would raise a hammer, which would strike upon a bell, to warn the
stoker that there was not enough steam. If, on the other hand, the steam was
too strong another hammer would warn the stoker by striking on another bell.
This arrangement is for the purpose of preventing accidents and economising
fuel. The hammers and bells have not been shewn in the Drawings, because
any intelligent mechanic will know how to arrange them; but I would observe
that a lever is fixed upon the axle of the segment rack v, for the purpose of
alternately raising these hammers, in order to prevent them from striking when
not required. If from any cause whatever the clock should stop, the throttle
valve on the supply pipe would become completely closed, because the wheel j
would carry round the segment rack until the last tooth. of the rack should be
raised so high that the wheel might turn without acting upon the throttle
valve or stopcock. All that has been mentioned relative to regulating steam
engines will equally apply to air engines, because the above described appara-
tus will act equally as well upon a cock as upon a valve. As to water engines
or machines, or wheels driven by the force of water, the regulating apparatus
is made to act upon an additional sluice or water gate constructed of sheet
iron, and which rises and falls perpendicularly in a groove in order to
change the level of the water and allow a greater or smaller quantity of
water to pass through and act upon the wheel. The manner of connecting

page_text: this additional sluice gate to the regulating apparatus, in order to make
it rise and fall in the groove, as the case may be, will readily suggest
itself to any intelligent mechanic, and it would be useless to point out any
particular method. as that constitutes no part of the Invention, and must evi-
dently vary according to the circumstances of the case; but it may be as well
to observe that the action of the additional sluice gate is rendered more easy
by the application of antifriction rollers in the groove, and employing a counter-
balance. If it is thought desirable or necessary to alter the number of strokes
of the piston of the engine, or the number of revolutions made by a water
wheel in an hour, it will only be necessary to lengthen or shorten the rod of
the pendulum, so as to increase or diminish the number of vibrations, as is
well understood.
Having now described the Invention that has been communicated to me,
I wish it to be understood that I lay no claim to the construction of the
clock, or any other part of the apparatus that is well known, nor do I intend
to confine myself to the precise arrangement of parts herein set forth and
described, but I claim as the Invention secured to me by the herein-before in
part recited Letters Patent, the construction of any apparatus for regulating
the speed of any motive power when such apparatus consists of differential
wheel work acted upon by two separate powers, such as the engine and the
weight, and governed by a clock movement, as above described.
In witness whereof, I, the said Jean Baptiste François Jouannin, have
hereunto set my hand and seal, this Ninth day of January, in the
year of our Lord One thousand eight hundred and forty-three.
FRANCOIS (L.S.) JOUANNIN.