CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1835

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
Lucy, of Birmingham, in the County of Warwick, Miller, send greeting.
WHEREAS His most Excellent Majesty King William the Fourth, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-fourth day of August, in the sixth year of His reign, did
give and grant unto me, the said William Lucy, my exors, admors, and
assigns, His especial licence, full power, sole privilege and authority, that I,
the said William Lucy, my exors, admors, and assigns, and such others as I,
the said William Lucy, my exors, aduiors, or assigns, should at any time
agree with, and no others, from time to time and at all times hereafter
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, my Invention of "CERTAIN IMPROVEMENTS IN STEAM
ENGINES;" in which said Letters Patent there is contained a proviso that I,
the said William Lucy, shall cause a particular description of the nature of
my said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in His said
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, reference
being thereunto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Lucy, do hereby declare the nature of my said Invention, and the
manner in which the same is to be performed, are fully described and ascer-
tained in and by the following description thereof, reference being had to the

page_text: Drawing hereunto annexed, and to the figures and letters marked thereon
(that is to say)-
It is well known that, according to the present modes of applying steam
engines to turn or work machinery, and in converting the alternating motion
thereof to ratatory motion by means of a crank, or by the aid of what is
known by the name of the sun and planet motion, the main shaft is not
made to rotate with an equable motion, owing to the velocity of the crank
varying in its revolution, (that is to say,) in those parts where the crank passes
over and under its axis of motion, the force of the steam in such cases is not
directly and fully applied, which causes considerable inequality of motion to
the main shaft. Various means have, however, been resorted to in order to
correct such inequalities of motion; but the only method now in general use
is the application of a fly wheel, which, taking up the excess of power of the
piston on the crank, when acted on by the steam in the most effective position,
gives off such collected power at those positions where it is required for making
the whole working of the crank more uniform. And in some instances a fly
wheel has been made to work with greater velocity than the main shaft by the
aid of a second motion, by which means the power of an engine has been
rendered more uniform than by having a heavier fly wheel on the main shaft;
but in each of these instances there still remains considerable inequality in
different parts of the rotation of the main shaft. Now, the object of my
Invention is to render the velocity of all parts of the rotation of the main
shaft more equable, by the application of a pneumatic pump, in combination
with valves and other apparatus, in order to insure the necessary vacuum in
such pneumatic pump, or by the application of the ordinary air pump of the
condenser to the second motion of the engine, or of the gravitating property of
a weight, through the means of a rod or lever, to a steam engine, as will be
hereafter fully described.
DESCRIPTION OF THE DRAWING,
Which represents the main shaft and crank with part of the connecting rod
of a steam engine, having my Invention applied thereto. a is a portion of the
connecting rod, proceeding from the main beam of a steam engine, the steam
cylinder of which is about thirty-three inches in diameter, with a six-feet stroke.
b is the main shaft; and c is the crank affixed thereto. d is a toothed
wheel, attached to the main shaft, which takes into and drives the toothed
wheel e, which is affixed on the shaft or axis e; the wheel e being of half the
diameter of the wheel d, and therefore revolves at twice the speed. f is
a connecting rod attached to a crank pin on the wheel c.
is capable of adjustment, there being holes by which the
This crank pin
same may be

page_text: set nearer to the centre of motion, and thereby shorten the crank so formed.
And it should be observed in setting this pin that a line drawn through the
centre of the wheel and the crank pin should always be at or near a right
angle to a line drawn through the crank and centre of the main shaft. And the
other end of the rod f is connected with the beam g, which vibrates on a
fulcrum in suitable bearings in like manner to the main beam of the engine.
h is the piston rod of the piston i, which works in what I call the pneumatic
cylinder ; the upper part of this cylinder being open, and the lower end
being closed, as is clearly shown in the Drawing. is a valve in the piston ¿,
opening outwards, by which means any air under the piston in the cylinder k
may pass off, if the other outlets should be closed when the engine starts.
m is a stopcock and pipe which connects the cylinder k.with the condenser of
the engine, by which means the state of vacuum in the cylinder k will be
governed by the vacuum in the condenser of the engine, which is a very
important feature in my Invention, and insures the correct working of the
engine. And it should be stated that where the engine is not a condensing
engine, then it will be desirable to have a small air pump in connection with
the cylinder k, to remove any air which would otherwise accumulate in the
working of the engine. n is a stopcock on a pipe from the cylinder k to the
atmosphere, by which any water or oil which may pass from the upper surface of
the piston (which is constantly kept covered with oil or water) may be drawn
off. It should also be stated that in place of using an additional pneumatic pump
to condensing engines in order to controul or correct the working of the crank, as
has been herein described, I sometimes, where circumstances will allow, prefer
to connect the ordinary air pump of the condenser to the second motion of the
engine; and in such case the cover at one end of the air-pump cylinder is to
be omitted, by which means the pressure of the air on the surface of the air-
pump piston will tend to equalize the motion of the engine in like manner to
the pneumatic pump k, and will at the same time greatly simplify the steam
engine; for it will be evident that the ordinary pump will thus, in addition to
working the condenser, perform the further process of equalizing of the rotation
of the main crank.
This part of my Invention is more particularly adapted to new engines; at
the same time it may be applied to old engines, where the convenience of
coustruction will readily allow of the air pump being connected with the second
motion of the engine.
Having thus explained the nature of the parts shewn in the Drawing (the
construction of which will be evident to an engineer), I will describe the
manner of action

page_text: The Drawing represents the crank as being at the top centre, and conse-
quently in the least favorable position; but it will be observed that the piston i
is at or near the middle of its stroke, and is therefore transmitting the pressure
of the atmosphero to the working of the engine to the fullest extent of its
power, and thus continuing the rotatory motion of the main shaft with a more
equable motion throughout; and as the pressure of the steam of the piston in
the steam cylinder of the engine becomes more and more favorable after the
centre is passed, it will be seen that the piston i in the pneumatic pump is being
raised in opposition to the pressure of the atmosphere; and such is the con-
tinued action of the engine, that the piston i is progressively retarding the
action of the piston in the steam cylinder when the steam is acting most
powerfully; and, on the other hand, the atmospheric air on the piston ? is pro-
gressively encreasing and decreasing its efforts in transmitting power to the
engine as the piston in the steam cylinder approaches to and passes from the
centre at each end of the cylinder. From the foregoing description it will
have become evident that although I prefer having the beam g and the piston
rod connected therewith by parrallel rods, a similar effect may be obtained
by connecting the rod f directly to the piston rod h, in place of transmitting
the power through the beam g, as above described; and it should be remarked,
that although I have shewn in the Drawing the parts drawn to a particular
scale, this may be varied, for it will be evident that the power of the pneumatic
pump will be more or less in proportion to its diameter when combined with
the velocity of the piston therein. This will, however, be evident, and will
readily be adjusted by an engineer, in making a new engine, or in applying my
Invention to an old engine, by observing the nature of the parts, and the descrip-
tion here given. It will be evident that in place of applying the pneumatic
pump to retard the working of the steam engine, and at the same time collect
power to be given off thereto at the required times, a weight may be applied
to the end of the lever g, which, being raised when the steam is acting most
favorably on the crank, will retard the working thereof, and by its gravity will
give off the power so obtained by descending when the crank on the main
shaft is passing over or under the centre of motion of the main shaft, and thus
will a more equable motion be obtained to the main shaft throughout the
whole of its rotation.
Having now described the nature of my Invention, I would remark that I
am aware that a fly wheel, having one portion of the circumference more
weighted than the other, and revolving at twice the speed of the main shaft,
has been before applied to a steam engine for equalizing the motion thereof,
but in such case the balance weight so added to the wheel in its rotation par-

page_text: takes of the rotatory motion of the wheel itself. But according to my Inven-
tion, when a weight is used, the same does not partake of the rotatory motion of
the wheel by which it is actuated; and I would further observe, that although
I have here described the engine as without a fly wheel, it is not essentially
necessary to abandon the same. But my Invention may be used in aid
thereof.
In conclusion, I would have it understood that I lay no claim to the various
parts herein described in their separate condition nor in combination, other
than for the purpose of carrying my Invention into effect. But what I claim
is the application of a pneumatic pump, when combined with suitable valves and
apparatus, for ensuring the vacuum therein; or, in place of such additional
pneumatic pump, I claim the application of the ordinary air pump of the con-
denser to the second motion of the engine, by which means such air pump is
caused to perform the double process of working the condenser, and also the
equalizing of the rotation of the main shaft or main crank of the engine.
And I claim the application of a weight to a lever, actuated by the second
motion of a steam engine, as above described.
In witness whereof, I, the said William Lucy, have hereunto set my
hand and seal, this Twentieth day of February, in the year of our Lord
One thousand eight hundred and thirty-six.