IMPROVEMENTS IN THE METHOD OF CONTROLLING THE SPEED OF ENGINES
Year: 1885

page_text: I RALPH HENRY CHRISTOPHER NEVILE of Wellingore Hall near Grantham
in the County of Lincoln Esquire do hereby declare the nature of any said inven-
tion for IMPROVEMENTS IN THE METHOD OF CONTROLLING THE SPEED OF ENGINES
to be as follows:-
This invention consists of an improvement which may be applied to any engine
in which the speed of the engine is wholly or partially controlled by a governor
operating a valve situated between the boiler or generator and the slide valve chest
whereby the steam or other fluid is throttled and reduced in pressure on its
admission to said valve chest-In this case the pressure in the valve chest will
vary in accordance with the work that the engine is performing and in this inven-
tion I cause the pressure in the valve chest to act upon the governor in such a
manner that as the work thrown on the engine and consequently the pressure in
the valve chest increases the governor has an increased tendency to open the con-
trolling valve and thereby the speed of the engine is rendered much more uniform
The variation of pressure in the valve chest may be caused to act upon the
Governor in a variety of ways according to circumstances and the description of
governor used.
For example the valve chest may be made to communicate with
a cylinder in which works a piston and the piston may either directly or through
a system of levers act upon the governor or the controlling valve. It may also be
made to communicate with a hollow spheroid which will tend to assume a more
spherical form as the internal pressure increases or with one or more elastic
diaphragms which will tend to move under the increased pressure or with a
flattened closed tube of the form used in a Bourdon pressure guage or with a spiral
tube In all these cases the pressure produced by a tendency to change of form
may be communicated by rods or levers to the governor or valve. We may also
instead of using the pressure in the valve chest alone use the difference of pressure
between the valve chest and that upon the other side of the controlling valve
either by causing the two pressures to act upon opposite sides of a piston or
diaphragm or other similar contrivance as before described or what I consider
preferable as being more perfectly adjustable by using two entirely distinct
apparatus the one operated by the pressure in the valve chest and the other by
I Umina Q71

page_text: that on the other side of the controlling valve and causing the two apparatus to
act in opposite directions upon the Governor or controlling valve either directly or
through any system of rods or levers that may be convenient-In this way the
running of the engine may be made independent of the initial pressure in the
boiler or generator as well as of the load In the case of an engine driving a
machine for the production of electricity the same arrangements may be applied to
maintain the electro motive force or the current sent out constant instead of
maintaining the speed of the engine constant.
The governors used may be centrifugal or electrical or indeed of any convenient
type as the principle of the invention does not depend so much upon the method
of application as upon the utilisation of the varying pressures in the valve chest or
of the varying differences of pressure between the inlet & outlet of the controlling
valve to the assistance of the governor.
It will of course be obvious that the size and power of pistons or other apparatus
used must be adjusted according to the governor and valve used and to the system
of levers through which the apparatus acts upon the governor and also that by
exaggerating the power of the apparatus the engine may be caused to run faster or
to give greater electromotive force or more current when a heavy load is on than
when a light one is on-Or on the other hand if found desirable that it may be
used in a reverse manner to exaggerate the natural tendency of the engine to run
slower as the load increases.

page_text: I RALPH HENRY CHRISTOPHER NEVILE of Wellingore in the county of Lincoln
Esquire do hereby declare the nature of my invention for IMPROVEMENTS IN THE
METHOD OF CONTROLLING THE SPEED OF ENGINES and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :--
This invention consists of an improvement which may be applied to any engine
or motor in which the speed is wholly or partially controlled by a governor.
operating a valve situated between the boiler or generator and the slide valve chest
whereby the steam or other elastic fluid is throttled and reduced in pressure on its
admission to the said valve chest-In this case the pressure in the valve chest
will vary in accordance with the work that the engine or motor is performing and
in this invention I cause the pressure in the valve chest to act upon the governor
in such a manner that as the work thrown on the engine and consequently.the
pressure in the valve chest increases the governor is given a diminished tendency
to close the controlling valve and in this manner the speed of the motor is rendered
much more uniform-This variation of pressure may be caused to act upon the
governor or controlling valve in a variety of ways according to the special descrip-
tion of governor or controlling valve used-For example in Figures 1 & 1ª is
shown a method of applying it to an ordinary High Speed Centrifugal Governor G.
controlling the admission of elastic fluid by means of a double beat Cornish or
other valve which has a tendency to rise and so to open when the pressure in the
boiler or generator or reservoir of elastic fluid is higher than that in the valve
chest In this case the spindle S of the valve has in it a slot upon the bottom of
which rests the small arm of a lever L L₁-Another arm of this lever upon the
same side of the fulcrum terminates in a palette upon which the spindle of the
centrifugal governor presses as the balls fly outwards & so tends to close the valve
by pressing downwards upon the spindle S-This spindle terminates in a cap C &
upon this rests a short rod R which is free to move up and down-This rod has at
or near its upper end a small roller A and upon this rests the arm of a lever B B,
whose fulcrum is situated at F. D₁ is a small cylinder the end of which below the
piston is in communication with the valve chest the piston rod of this cylinder
passes freely through the cap of the cylinder which only acts as a guide and
terminates in a small roller which bears against the lever B B, as shown― at B₁ is
a weight W, suspended-It will be evident that as the pressure in the valve chest
rises in consequence of increased work being done by the motor the piston rod of
the cylinder will press with an increased force upon the lever & will thus relieve

page_text: the valve spindle S of a portion of the downward pressure produced by the
weight W, acting through the lever B B₁. In consequence the spindle S will be
able to rise further while the balls of the governor continue rotating at the same
speed and thus the valve will open wider to allow for the increased requirements
of the motor while maintaining its speed without material alteration. A preferable
arrangement is however shown in Figure 2. The weight W, is removed & a second
cylinder D, is placed acting in a similar manner to the cylinder D₁ upon the
lever B B, but upon the other side of the fulcrum F-This cylinder has its lower
portion in communication with the boiler or reservoir of elastic fluid and as long as
this pressure remains the same the action is precisely similar to the action above
described but if the pressure in the boiler or reservoir varies this arrangement will
also compensate for such variation-For it will be seen that when the pressure in
the boiler or reservoir diminishes the pressure on the piston rod belonging to the
cylinder D, also diminishes & thus the lever B B₁ presses with a diminished force
upon the valve spindle S and thus allows the valve to open wider to allow for the
diminished pressure under which the steam or other clastic fluid has to pass it—
The size of these cylinders & their respective pistons and their respective distances
from the fulcrum F will vary in accordance with the species and size of valve used
as to whether it be a valve in perfect equilibrium with the exception of its spindle
or whether it be one having such differences of area on its faces that it will require
compensation for such differences and also in accordance with any spring or
variable resistance there may be in the governor itself and these sizes and distances
will generally require to be determined for any particular form of governor by
experiment-It may occur that the pressure downward on the valve spindle
exerted by the lever will exceed the upward pressure of the valve produced by the
pressure of the steam or elastic fluid thereon and in this case it becomes necessary
to place a weight W, upon the lever as shown so as to cause the valve to have always
a tendency to open-Or in the place of a weight upon the lever a spring or counter-
balance weight may be applied so as to act upon the rod R & give it an increased
upward tendency-It is also possible to use one cylinder instead of two the
cylinder on one side of the piston (being in communication with the boiler or
reservoir & that on the other with the valve chest and in this case the differences
of pressure are obtained by a proper adjustment of the relative sizes of the cylinder
with its piston & of the piston rod-This may be placed on either side of the
fulcrum F of the lever B B, according as the upper or lower end of the cylinder is
in communication with the valve chest.-A cylinder acting in this manner is shown
in figure 6 although in this case it is arranged to act directly upon the valve
spindle without the intervention of any lever-Instead of a piston moving within
a cylinder we may also use an elastic diaphragm fixed therein with a rod resting
upon it or attached thereto, the other end of this rod either directly acting upon the
valve spindle as in Figure 8 or acting through a lever-One side of this diaphragm
would then be in communication with the boiler or reservoir and the other with
the valve chest-The lever arrangement is preferable as being more easily capable
of adjustment but as shown it is not absolutely necessary as where one cylinder
only is used this may be placed vertically above the valve spindle & the rod may
then act directly upon the valve spindle.
In Figures 3, 4 & 5 the cylinders are substituted by other forms of diaphragms
and tubes having a tendency to change their forms under varying pressures and so
to produce varying forces acting upon the lever B B₁ & thus upon the valve
spindle S any other shape having the same tendency to change of form may also
be substituted and they may be caused to act directly upon the valve spindle or
through a lever.
In Figure 7 another arrangement is shown in this the governor is placed directly
over the valve spindle S so that the spindle of the governor presses directly upon,
the top of the spindle S or upon a cap as shown-The lever B B, has its fulcrum
at F and one arm of it works in the slot in the valve spindle upon the other arm.

page_text: is fixed the weight W, & upon it also press the rods attached to the two cylinders,
diaphragms or other forms D, & D. These are shown vertically opposite to
each other but they may be placed so as to act upon different parts of the lever B B₁
at different distances from the fulcrum F according to the relative strength that it
is necessary they should have or they may be placed opposite to each other if
made of suitable sizes. The cylinder or other form D₁ might also be inverted &
inade to act upon a prolongation of the lever B B, in the direction B₁.
In Figure 9 is shown the method of application to an automatic expansion gear-
In this the two cylinders or other forms act upon the lever B B, which has a fork
upón it which rests upon the collar of the centrifugal governor G. This lever is
connected by means of the rod H to the rod K which has at the one end a block
working in the quadrant Q and is at the other end connected to the expansion
valve either directly or through a system of rods & levers the quadrant Q receiving
its motion in the ordinary way from an excentric. The action here is similar to
that above described.
When the load on the engine or motor increases or when the pressure in the
boiler or reservoir diminishes the lever tends to cause the block to move lower
down in the quadrant Q and thus to give a longer stroke to the rod K & so to give
a later cut off to the expansion valve.
It will be understood by the above descriptions that I do not confine myself to
the particular forms or methods of application described as they may be almost
indefinitely varied by any one acquainted with this branch of mechanics according
to the special form of governor used and to special requirements.
When an expansion valve is used as a means of governing the pressure in the
valve chest is approximately the same as that in the boiler or reservoir and there-
fore in Fig. 9 the cylinder D, instead of being in communication with the valve
chest is in communication with a separate reservoir which communicates by means
of a small pipe with one or both ends of the main cylinder of the motor-It will
be evident that the pressure in this reservoir will increase as the valve cuts off
later & as in consequence the mean pressure in the main cylinder increases.
It will be evident that this system may be applied not only to cause the engine
or motor to run at a uniform speed but if necessary to run faster when an increased
load is put on this being simply attained by giving the cylinder D, greater power
either by increasing its size or its leverage than would be necessary to cause it to
run at a uniform speed-This is frequently of advantage in the case of motors
used for driving dynamo machines where it is often required that the dynamo
machine should run faster when there is a heavy load on to maintain a uniform
electromotive force or current as may be required.
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
1st The use of any system connected with the controlling valve or governor gear
of an engine or notor in which the speed is wholly or partially controlled by a
valve between the boiler or generator or reservoir of elastic fluid and the valve
chest whereby the varying pressure in the valve chest is utilised to cause a varying
pressure or force to act upon the controlling valve or governor gear in such a
manner as to maintain the speed uniform with varying loads or to cause it to vary
in any desired manner.
2nd The use of any similar system applied to an automatic expansion gear
whereby the mean pressure in the cylinder of the motor is utilised to cause a
varying pressure or force to act upon the governing gear in such a manner as to
keep the speed uniform or cause it to vary in any desired manner.
3rd The use of any similar system in which the pressure in the boiler or
reservoir of elastic fluid and that in the valve chest or the mean pressure in the
main cylinder are together caused to act with varying force upon the governor

page_text: gear & so to cause it to maintain the speed uniform or cause it to vary in any
required manner.
4th The use of the various apparatus figured in the drawings attached hereto
and numbered 1, 14, 2, 3, 4, 5, 6, 7, 8 & 9 or any similar arrangements substantially
as above described for the purpose of keeping the speed of the engine or motor
uniform or causing it to vary in any required manner.
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