IMPROVEMENTS IN REGULATING THE SPEED AND INDICATING AND AWED MOTIVE POWER ENGINES
Year: 1853

page_text: LETTERS PATENT to Alexander Clark, of Gate Street, Lincoln's
In Fields, in the County of Middlesex, Engineer, for the Inven-
tion of "IMPROVEMENTS IN REGULATING THE SPEED AND INDICATING
AND AWED MOTIVE POWER ENGINES"
Sealed the 23rd January 1854, and dated the 25th July 1853.
PROVISIONAL SPECIFICATION left by the said Alexander Clark
at the Office of the Commissioners of Patents, with his Petition,
on the 25th July 1858.
T. ALEXANDER CLARK, of Gate Street, Lincoln's Inn Fields, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN REGU-
LATING THE SPEED & INDICATING THE POWER OF STEAM AND OTHER MOTIVE
POWER ENGINES" to be as follows:-
My Invention of improvements in regulating the speed of engines
consists, firstly, in actuating the throttle valve or other contrivance for
regulating the flow of steam or other source of power to the engine,
by the variation of power transmitted through the main shaft or other

page_text: prime mover, and wholly irrespective of any alteration of the speed.
I cause the variation of power transmitted through the main shaft or
other first mover to take effect on an apparatus, the action of which
operates on the throttle valve or other analagous contrivance; the flow
of steam or other source of power will thus be regulated according to
the power required.
The action is this:-When the power communicated by the main
driving shaft increases the throttle valve will be caused to open, and
when the power transmitted through the shaft beconies less the throttle
valve will become closer, and so maintain a uniform degree of speed in
the engine. This takes place totally independant of any increase or
decrease of speed of the engine, and is entirely the result of the amount
of power transmitted through the main shaft or other first mover to
which the apparatus by which this object is affected is applied. The
principle of action of the apparatus, of which there may be numerous
modifications, is entirely new as applied to regnlate the speed of motive
power engines. The same or similar apparatus, by the application of
an indicator card and tracing point and index, is adapted for measuring
and indicating the amount of power transmitted.
Another improvement in regulating the speed of engines consists in
the employment of a float resting in a chamber of water or other fluid,
which float is moved by the rising and falling of such fluid, and acts on
the throttle valve or other contrivance which regulates the supply of
steam or other source of power. The vessel of water which I use has two
compartments, in one of which the float is placed; the other is simply
a receptacle for the fluid. In the partition separating these two com-
partments I place an archimedean screw, which has a quick rotatory
imparted to it by the engine. This exerts a certain force on the water,
and will produce a difference in the level of the fluid in the two com-
partments, which difference will be more or less according as the rate of
motion increases or decreases. Instead of using a screw to act on the
fluid, a rotating fan or other apparatus which will propel the fluid by
centrifugal force may be used. The velocity of the screw or fan, viz.,
the number of revolutions, is much greater than the rate of the engine,
consequently any slight diminution or or increase of speed in the engine

page_text: is multiplied and quickly effects the level of the fluid, and is accom-
panied by a corresponding action of the float which operates on the
throttle valve.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Clark in the Great Seal Patent
Office, on the 25th January 1854.
TO ALL. TO WHOM THESE PRESENTS SHALL COME, I,
ALEXANDER CLARK, of Gate Street, Lincoln's Inn Fields, in the County
of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of July, in the year
of our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her leirs and successors,
give and grant unto me, the said Alexander Clark, Her special licence
that I, the said Alexander Clark, executors, administrators, and
assigns, or such others as I, the said Alexander Clark, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
REGULATING THE SPEED AND INDICATING THE POWER OF STEAM AND OTHER
MOTIVE POWER ENGINES," upon the condition (amongst others) that I,
the said Alexander Clark, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW. YE, that I, the said Alexander Clark, do hereby
declare the nature of my-said Invention, and in what manner the same
is to-be-performed, to be particularly described and ascertained in and

page_text: by the following statement, reference being had to the Sheet of Draw-
ings hereunto annexed, and to the letters and figures marked thereon
(that is to say):
My Invention of improvements in regulating the speed of steam
engines and other machines in which motive power is generated, con-
sists in regulating the flow of steam or other source of power to the
engine, according to the amount of power required at any given time,
and continuously during the action of the machine.
The action of the apparatus which I employ to regulate the motion
of machines is dependant on the variation of power transmitted' through
the main shaft or other prime mover, and is wholly irrespective of the
rate of motion or any alteration of speed, the object being to maintain
any fixed and unvarying number of revolutions required.
In the apparatus or governor hitherto adopted for regulating the
speed of engines, it is in itself dependant for its action upon that very
irregularity of motion which it is intended to prevent; to attain any
great degree of perfection by such means is therefore impossible. Ac-
cording to my Invention I cause any variation of power transmitted
through the main driving shaft or other first mover in a steam engine
to take effect upon the throttle valve, through the intervention of an
apparatus sensible to such irregularities, which has the effect of opening
or closing the throttle valve in a manner to so regulate the passage of
steam as to maintain a constant counterpoise between the power
generated and the power absorbed, and thereby an unvarying velocity
of motion in the machine.
The annexed Sheet of Drawings represent the manner in which my
Invention may be carried into effect. Fig. 1, represents a side elevation
of a steam engine, with apparatus for regulating the speed according to
my Invention and Fig. 2, a back view of the same. ", is the main
shaft of the engine, which, as far as the bevil wheel b, is the same as
heretofore; the shaft c, is the continuation of the prime mover, but
which is separate and distinct from the shaft a. The shaft c, is sus-
tained by suitable and independant bearings, with the end butting
against the end of shaft a. A socket d, is placed on the ends of these
shafts, on which it turns as a centre. The socket carries on one side a

page_text: pivot or stud e, which supports a bevil wheel f. This wheel f, geers
into the bevil wheel b, and is the only medium through which the power
of the engine is transmitted to the wheel g, fixed on the shaft c, by
which the power is communicated to the purposes required.
The boss d, has also an arm h, extending from the opposite side to
stud e. This arm h, is extended to a considerable length, and is placed
in connection with the piston i, in the cylinder k, whereby a certain and
increasing amount of resistance is offered to the rise of lever h. The
pistoni, is furnished with a cup leather, to prevent air passing from the
upper to the lower part of cylinder k, which is otherwise rendered air-
tight. When the engine is at rest the lever arm h, is at its lowest
point, the piston i, being then at the bottom of the cylinder k, where
there is little or no resistance offered to the rise of the piston. When
the engine is set in motion, the rotation of bevil wheel b, is commu-
nicated to f, mounted on the stud e, forming the opposite end of lever
h; the wheel f, is carried round and rises from the position shown in
dotted lines at Fig. 2, and carries with it the lever h, round on the
socket d, as an axis, thus raising the piston i, which compresses the air
in the cylinder above the piston, and rarefying any air that may be
below and the cylinder being air-tight the resistance regularly and
gradually increases, until the force opposed to the rise of lever arm h.
balances the force necessary to produce (by means of wheel f.) motion
in the bevil wheel g, and its shaft c. P, is the steam pipe, and 1, the
slide or throttle valve, which is placed in connection with the piston
rod of i, by means of the lever m, mounted on a fixed fulcrum
at . This connection, like the ordinary connection of the go-
venor and throttle valve, has the effect of opening and closing
it entirely. A temporary communication o, is provided, by which
steam is first allowed to enter the steam cylinder, and induces notion
of the engine. The power of the engine having been thus exerted,
takes effect upon the governing apparatus, as before described, and
so as to open the throttle valve. The resistance of piston i, to
the rise of lever h, is arranged to open the throttle valve, so as
to permit such amount of steam to pass as will impart a given
rate of velocity. For instance, suppose the engine is running light,

page_text: it will then attain its rate of motion with very little force exerted
to carry the wheel f, round in the direction of the red arrow, and.
consequently with very little rise in the piston; the least possible
opening in the throttle valve sufficing to pass the steam necessary for
such rate of motion. The engine load being increased more power is
transmitted through wheel f, which consequently exerts a greater
downward force on its stud e, and is carried round further in the:
direction of the red arrow, and until the throttle valve is opened
enough for the passage of steam to overcome the increased resistance,
and maintain the same rate of revolution in the engine. Any further
increase in the load of the engine is attended with a similar effect on
the governor and throttle valve and continued uniformity of speed.
When throwing off or diminishing the load of the engine the com-:
pressed air above the piston ?, and vacuum below, carries the lever h,
and wheel f, back towards their original position, the effect of which is,
to contract the passage of the throttle valve and limit the passage of
steam to the amount required for the reduced load, but still main-
taining the same speed of the engine and machinery: From the-
foregoing it will be understood that the first effect of any variation of
the power transmitted is upon the goyenor, to which it is constantly
sensible, producing the necessary change in the throttle valve, which
will at all times maintain a uniform rate of speed in the engine.
Fig. 8, is an end view of an engine shaft and geering of another
arrangement of govenor; Fig. 4, a side view; and Fig. 5, a plan
and partial section of the same. a, is the engine shaft, which, as.
before, is in line with, but separate from, the shaft.c. On shaft c,
a wheel, is fixed, which has an internal rim of teeth 1, 1. The
engine shaft a, has a smaller wheels, fixed on it. This shaft, though
entering the eye of wheel is not fixed thereto. A pinion t,. geers
with the wheels, and with the teeth r,, of q, simultaneously. This s
pinion t, which performs a similar office to f, in Figs. 1, & 2, is
mounted on an axis u, which is supported on the short end of a lever v.
in communication with the throttle valve lever m. The lover w, iš
simply a second support for pinion t, and is. united to v. a, is a box
of weights in lieu of the air. cylinder. k, before explained. The.

page_text: power of the engine is transmitted from wheels, through the pinion.
t, to the wheel, and thence through the shaft c, to the object
desired; according as the power to be transmitted is greater or less, so
will be the force exerted to carry round the axis of pinion t, in the
direction of the red arrow. The consequent depression of that end of
lever v, elevates the long end, and with it the weights a, a, which
restrict and act upon that lever in manner similar to the air cylinder.
of last illustration. The weights a, a, rest in a box on a series of
steps, the rod y, passing through them, and fixed only to the lower one,
which is of sufficient weight to close the throttle. The engine is started
by the temporary opening of a steam passage, before explained, and,
when running light the throttle is kept sufliciently close by the lower
weight a; the amount of downward force applied to the short end of
lever v, by the transmission of power, being insufficient to raise a second
weight. On any increase of tlie load taking place the downward
tendency of t, is augmented, raising the long end of lever v, and with
it the next weights in succession as the lower ones raise up to them,
this being accompanied by a further opening of the throttle valve,
enabling the engine to overcome the increased resistance. On any
reduction of the engine load taking place a reaction of the foregoing,
is produced, and a consequent closing of the throttle valve. The
graduation of the weights a, a, and the rise between cach, must.bc.
regulated so as to produce with, the greatest exactness the necessary
opening and closing of the throttle valve to maintain the uniformity of
speed desired. To prevent the sudden increase or decrease of the.
weight the several plates or weights a, a, may be alternately inclined:
in opposite directions, so as to touch each other, by which arrangement:
increase or decrease of weight will be continuous with the upward "or
downward motion.
:
Fig. 6, represents an arrangement of govenor, according to my:
Invention, in which the power of the engine is communicated by a
strap. u, is the engine shaft; b, the shaft which receives the motion;
and c, the strap whereby power is transmitted. In driving by an
endless strap, that part of the strap travelling towards the driver is
subject to greater or less tension, according to the power transmitted, :

page_text: and will therefore require more or less force to deflect it from a straight
course. d, is a wheel or drum of larger diameter than the driving drum
e, which drum d, keeps the opposite sides of the strap at a given sepa-
ration. The drum d, is connected with the shaft a, by arins f, f
one on either side, but rests on the lower part of the strap, against
which it is also drawn down by a spring, so that when the engine is at
rest the lower part of the strap is at its greatest deflection downwards.
Immediately the machine is set in motion, and power transmitted to the
drum h, on shaft b, tension of the lower part of strap c, takes place,
and so elevates the drum d. The elevation of drum d, is more or less
according to the tension of the strap, but which must be so arranged
that some little deflection remains, even at the extreme of power trans-
mitted. The spring g, of necessity increases its power as it becomes
further distended, which increase should be so regulated to the require-
ments of the apparatus to which motion is to be given, and as before
explained with reference to the weights. The rising and falling of the
drum d, takes effect upon the throttle valve of the steam engine through
the intervention of the bell crank lever i, and rod k, with which it is
connected. When at the lowest point the throttle is closed, and when
at the highest it is opened to its fullest extent. This same apparatus is
also adapted for indicating the power communicated from the first
mover. To indicate the power transmitted it is simply necessary to
make use of the lever arm h, of Figs. 1, & 2, or lever v, of Figs. 3,
4, & 5, or a pointer whose motion is regulated by that instrument,
which, with an index suitably graduated, will indicate by its position
thereon the amount of power transmitted. A register of the power
transmitted may be produced by means of an indicator card in the
ordinary manner. This index must of course be graduated according
to the power of the engine, ascertained by calculation or otherwise
practically determined.
In the foregoing description, the spring, air cylinder, and weights, it
will be apparent, are mere equivalents to each other; but I may
observe that I prefer the use of the weights, as presenting a better
opportunity for graduating the counterpoise in a manner to produce
more perfect regularity of motion.

page_text: I may also add, that although I have used the term "throttle
valve," expressing the valve for regulating the admission of steam, that
I use a slide valve for the purpose, in preference to the ordinary
throttle valve.
Having described the nature of my Invention, and the mode of
carrying the same into effect, I would have it understood that I claim
as my Invention, regulating the motion of motive power engines by the
agency of and by the variation of power transmitted, and also measuring
and indicating the power, as described.
In witness whereof, I, Alexander Clark, have hereunto set my
band and seal, this Twenty-fifth day of January, in the year of
our Lord One thousand eight hundred and fifty-four.
5
ALEX CLARK. (S.)
Witness,
W. CLARK,
53. Chancery Lane, London,
Agent for the Patentee.